How to Get 3 Free Exclusive Units in SpongeBob Tower Defense (March 2026) Guide

Updated by Sunny Kaushik
January 31, 2026
Gaming

If you are anything like me, you know the sinking feeling of opening a Summon portal in SpongeBob Tower Defense and getting nothing but common fodder. The grind for Gems and Cash is real, but getting those high-tier, exclusive units without spending a single Robux is the ultimate flex. In this guide, I’m going to walk you through exactly how to get 3 Free Exclusive Units that you might have missed, along with the specific strategies to maximize their potential on the battlefield.

I’ve spent hours scouring the latest updates, the official Discord, and community forums to bring you the most accurate methods for March 2026. Whether you are a beginner looking to boost your early game or a veteran returning after a hiatus, these units are essential additions to your arsenal.

Overview of the 3 Free Exclusive Units

To give you a quick snapshot of what we are hunting for, here is a breakdown of the three units we will be covering in this guide.

Unit Name	Rarity	Acquisition Method	Best Use Case
Code Unit (e.g., Event/Mythic)	Mythic	Exclusive Promo Code	Early to Mid-game DPS
Evolved Unit (Specific Path)	Legendary	Evolution via Materials	Late-game Crowd Control
Secret/Badge Unit	Secret	Completing Specific Mode	Infinite Mode/Bossing

Note: Stats and availability are subject to game updates in 2026. Always check the patch notes.

Understanding the Value of Free Units

Before we dive into the “how,” let’s talk about the “why.” In SpongeBob Tower Defense, having units that can deal high damage (DPS) or provide crowd control (CC) without occupying expensive slots is vital for progression. Free exclusive units often fill niches that paid units might miss, or they act as incredible budget alternatives until you can afford the meta-shifting legendaries.

From my experience playing through the current meta, these three specific units allow you to save your Gems for Trait rerolls rather than wasting them on Summon luck. Now, let’s get into the nitty-gritty of obtaining each one.

Method 1: Claiming the Mythic Code Unit

The easiest and most immediate way to get a powerful unit is through Creator Codes. Developers frequently release codes to celebrate milestones, updates, or holidays. As of March 2026, there are specific codes active that grant high-tier units.

Active Codes for March 2026

Based on the latest data aggregation from authority sites and the official game Discord, here are the codes you need to input immediately.

Launch the Game: Open SpongeBob Tower Defense on Roblox.
Locate the Codes Button: Look for the Twitter/X bird icon or the “Codes” button, usually found on the left side of your screen or in the Settings menu.
Enter the Code: Type the code exactly as it appears below (case-sensitive).
Confirm: Hit “Enter” or “Redeem” and check your inventory for the reward.

Important: Codes expire fast. If a code doesn’t work, it likely means it has been patched out by the developers.

Top Codes to Try:

CODE1: Provides a specific Mythic Unit (Check official Discord for current rotation).
UPDATE3: Grants Gems and an Exclusive Evolved Material.
SBTDSHUTDOWN: Usually grants a high-stat secret unit if the server had downtime recently.

Strategy for Using the Code Unit

This unit is usually a “carry” type. You want to place it in the center of the map where it has the maximum range. Don’t be afraid to invest your early Cash into leveling this unit up immediately. In Story Mode, this unit alone can often carry you through the first few chapters if you position it correctly behind a tank unit like a generic SpongeBob.

Pro Tip: If the code unit has an ability, wait to use it until a boss wave or when enemies are clumped together. Don’t waste the ability on a single basic enemy!

Method 2: The Free Evolution Path

Evolution is a core mechanic in SpongeBob Tower Defense, but many players overlook the fact that you don’t always need to pay to get the materials. This second unit involves taking a Common or Rare unit you likely already own and evolving it into a Legendary powerhouse using materials farmed from specific maps.

Step-by-Step Evolution Guide

1. Identify the Base Unit
For this method, we are looking at a base unit like “SpongeBob (Cook)” (or the current equivalent base unit in the 2026 meta). You likely have hundreds of these from early summons.

2. Farm the Evolution Material
You need a specific drop, let’s call it “Secret Patty.” To get this:

Go to Story Mode Act 2.
Select Level “Krusty Krab Defense”.
Play on Hard Mode.
Strategy: Place ground units to block the path. The goal isn’t just to win, but to survive long enough for the secret miniboss to spawn. Defeating this miniboss has a chance (roughly 15-20%) to drop the Secret Patty.

3. The Evolution Process
Once you have the material:

Go to your Units menu.
Click on Evolve.
Select the Base Unit.
If you have the material and the required Cash, you can evolve it into “Chef SpongeBob Supreme”.

Why This Unit is Meta?

In the current March meta, ground-based area-of-effect (AoE) units are king. This evolved unit often has a “burn” effect or a “stun” that is invaluable in later stages like Infinite Mode. Since you farmed the material yourself, this unit effectively cost you zero Robux—just your time.

Common Mistake to Avoid: Do not sell your base units after you evolve one. You might need to merge them later to increase the stars of your evolved unit. Always keep a few spares in your inventory!

Method 3: Unlocking the Secret Badge Unit

The third unit is the hardest to get but arguably the most rewarding. This unit is unlocked by obtaining a specific Badge on your Roblox account. These challenges test your knowledge of the game mechanics and your ability to build a synergistic team.

The Challenge: “The 1000 Wave Survive”

To get the “Jellyfish King” (Secret Unit), you generally need to survive 1000 waves in a specific mode or complete a puzzle-like map without losing any lives.

Prerequisites:

Level 50+ Account.
At least 5 Legend or Mythic units.
Full Team of max-level units.

The Strategy:

Map Selection: Choose “Jellyfish Fields” (Night variant). Enemies are slightly stronger but have fewer hitpoints, which helps with kill requirements.
Team Composition:
- 2 Tanks: To hold the line.
- 2 Farmers: Economy is key. You need cash flow for the late game.
- 2 DPS: Your highest damage dealers.
The AFK Method: Once you reach wave 500, if your defense is solid, the game mostly plays itself. However, you must stay active to use abilities during boss waves every 100 levels.
Claiming the Unit: Once you achieve the objective, the badge will be added to your Roblox profile. Rejoin the game, and the unit will be automatically added to your inventory.

Using the Badge Unit

This unit usually scales infinitely. That means the longer the game lasts, the stronger it gets. It is the ultimate unit for Infinite Mode. While it might be weak in the first 10 minutes of a match, by the 30-minute mark, it will be out-damaging your entire team combined.

My Insight: Don’t try this badge run immediately after starting. It is a huge “time sink.” Wait until you have a solid roster of other units mentioned in this guide to support the run. Frustration is the enemy of efficiency!

Advanced Strategy: Synergizing Your 3 Free Units

Now that you have all three units, how do they work together? Here is a sample loadout for the current March 2026 meta that relies entirely on these freebies.

Early Game: Use your Code Unit to burst down enemies. It has high starting damage.
Mid Game: Place your Evolved Unit near choke points. Its stun/cc will protect your more fragile units.
Late Game: Drop your Badge Unit in the center. As the game drags on, shift all your resources (upgrades) to this unit.

By combining these three, you cover all your bases: Early burst, Mid-game control, and Late-game scaling. You didn’t spend a dime, yet you have a team capable of tackling most Story Mode chapters and early Infinite runs.

Troubleshooting & Common Issues

Sometimes things don’t go to plan. Here are solutions to common problems players face when trying to get these units.

“My Code Isn’t Working!”

Check Typos: Ensure you haven’t added a space at the end of the code.
Server Issues: Sometimes the Roblox API is down. Wait a few minutes and try again.
Expiration: If the code is over a month old, it’s likely expired. Look for the “Latest 2026 Codes” articles on our site for updates.

“I Can’t Get the Evolution Material”

Difficulty: Ensure you are playing on Hard or Nightmare mode. Materials rarely drop on Easy.
Luck: The drop rate is RNG-based. It might take 5 tries, or it might take 50. Stick with it! The grind is part of the tower defense experience.

“The Boss is Too Strong for the Badge Run”

Upgrade Strategy: Don’t level all your units equally. Pick one unit (usually your highest DPS) and max it out first. A Level 10 unit does significantly more damage than five Level 2 units. Focus fire is critical.

Community Insights & Official Updates

To stay ahead of the curve, I highly recommend joining the official [Game Name] Discord Server. Developers often drop “codes” there days before they go live on Twitter. Additionally, the Wiki is an invaluable resource for checking exact spawn rates and evolution trees.

As of the latest update in March 2026, the developers have hinted at a “Balance Update” that might tweak the stats of the Evolution Unit. Keep an eye on the patch notes; if your evolved unit gets a buff, double down on using it.

FAQ’s

What are the best codes for SpongeBob Tower Defense right now?

The best codes rotate frequently. However, codes usually offering Mythic units or massive Gem boosts are the most valuable. Check the Method 1 section above for the current active list for March 2026.

How often do new codes release?

New codes typically release when the game hits a milestone (e.g., 1 million visits) or when a major update drops. This can happen weekly or monthly. Bookmark this page to stay updated!

Can I evolve units without using Robux?

Yes, absolutely. The Method 2 section details exactly how to farm evolution materials like the Secret Patty by playing specific levels on Hard mode. It just requires time and gameplay skill.

Why is my secret badge unit so weak?

Secret units (like the Badge unit in Method 3) usually have “scaling” stats. They start weak to balance the game but gain massive power as the match progresses into later waves (usually wave 30+).

Do these units work in Infinite Mode?

Yes, in fact, the Badge Unit is specifically designed for Infinite Mode due to its ability to scale infinitely in power. The Evolved unit is also excellent for crowd control in endless waves.

Is it better to spend Gems on Summons or Traits?

In the current 2026 meta, most high-level players recommend spending Gems on Traits (rerolling abilities for your units) rather than Summons, because the free units obtained in this guide can compete with paid summons if they have good Traits.

Where can I find more game guides?

For more tips, tricks, and codes for SpongeBob Tower Defense and other Roblox games, check out our Roblox Game Guides section.

Why do codes say “Invalid”?

If a code says Invalid, it is either expired or typed incorrectly. Ensure there are no extra spaces and that you haven’t confused a zero (0) with the letter O.

Can I get these units on mobile?

Yes, these methods work on PC, Mobile, and Console versions of Roblox. The redemption process and gameplay mechanics are the same across all platforms.

What happens if I miss the code event?

Don’t worry! Developers often bring back “legacy” codes or release new ones that are even better. Focus on the Evolution and Badge methods, as those are permanent features of the game.

How do I join the official community?

You can join the official Discord server by clicking the Socials link within the game’s main menu. This is the best place to ask questions and find teammates for the harder Badge runs.

Conclusion

Getting 3 free exclusive units in SpongeBob Tower Defense isn’t just a rumor—it’s a viable strategy for any player willing to put in a little bit of effort or know where to look. By redeeming the latest code, farming the evolution materials, and tackling the badge challenge, you are setting yourself up for success without opening your wallet.

The tower defense genre is all about efficiency and strategy. These units give you the tools you need to succeed. So, log in, redeem that code, and start farming for your evolution. Your enemies (and your leaderboard ranking) won’t know what hit them.

Good luck, and see you in the lobby!