SpongeBob Tower Defense how to get secret units: Roblox Guide

Secret units in SpongeBob Tower Defense on Roblox are obtained through specific summoning banners, crate openings, prestige progression milestones, and player-to-player trading. Unlike standard mythics or legendaries, secrets require specialized currencies such as Magic Conches, Karate Coins, Prestige Tokens, or low percentage drop rolls on standard banners.

Players can also shorten the grind by trading existing high-tier units in the trading plaza or utilizing dedicated secret luck game passes.

Overview of Secret Units and Acquisition Methods

The game features multiple secret units across different updates, each tied to distinct gameplay systems.

Summoning Secret Units on Banners

Summoning on banners is the most direct path for summonable secrets, though each banner requires different currencies and offers distinct odds:

Cyborg Plankton (Standard & Boosted Banner)

Cyborg Plankton is summoned from the standard gacha banner using Gems.

• Base Drop Chance: 0.025% on the regular banner.
• Boosted Banner Chance: Increases to 0.03%.
• Strategy: Because the base rate is 1 in 4,000 pulls, players typically save tens of thousands of gems from story stages, quest completions, and AFK farming. Activating Auto-Sell for common and rare tiers prevents inventory clutter during 50-pull batches.

Dream Gary (Exclusive Banner)

Dream Gary appears on the Exclusive Summon banner rather than the standard gem banner.

• Currency Required: Magic Conches.
• Drop Rate: 0.04% per summon.
• Acquiring Magic Conches: Magic Conches cannot be purchased directly with basic coins. They are earned by completing map patches, claiming daily quests, clearing achievements (which award up to 100 Magic Conches when maxed), finding them in Treasure Chests, and purchasing them from the in-game merchant.

Gorilla (Premium Banner)

Gorilla is a secret unit summoned through the Premium Summon banner.

• Currency Required: Premium Dice.
• Summoning Mechanics: Premium Dice can be obtained from admin drop boosts, playtime rewards, or the developer shop.

Unlocking Spongehenge via the Prestige System

Spongehenge cannot be summoned through standard banner crates. It is strictly tied to game progression in the Prestige area.

1. Locate the Prestige Cave: Walk past the starter pineapple house near the kelp area to enter the Prestige Cave.
2. Hit Level 100: Level up your player rank to 100 by playing story mode, challenges, raids, or AFK grinding.
3. Reach Prestige Level 10: Enter the prestige circle to reset your rank. You must complete this progression cycle repeatedly until reaching Prestige 10.
4. Prestige Shop Option: Inside the Prestige Cave, players who have unlocked the tier can also buy Spongehenge directly from the Prestige Shop using Prestige Tokens (100 tokens for the standard version, or 250 tokens for a Shiny Wombo variant).

At base level 1, Spongehenge deals 8,250 damage per attack cycle (striking 10 times per attack) with full area-of-effect (AoE) coverage, making it one of the strongest defensive towers for Endless mode.

Crates and Event Secret Units

Several secret units are tied to rotational crates and specialized game modes:

Master Udon (Tower of Karate Crates)

Master Udon drops from Karate Crates purchased with Karate Coins on Karate Island.

• Crate Odds: 1 in 200 (0.5% chance) per Karate Crate.
• Grinding Karate Coins: The most efficient method demonstrated by high-level players is speed-clearing Floors 80–90 of the Tower of Karate. A coordinated party equipped with Draconic Gloves can clear these floors in under 30 to 40 seconds per run, netting hundreds of coins per replay.

Sir Pinchelot (Secret Chests)

Players can obtain Sir Pinchelot by opening Secret Chests. These chests are earned as daily quest milestones (such as finishing raid and challenge quotas), high-difficulty story clears, and playtime gift timers.

Game Passes That Boost Secret Odds

For players looking to increase their statistical chances, the developer (Krabby Krew) offers several official game passes in the Roblox store:

• Secret Hunter (1,249 Robux): Officially listed to provide increased chances of discovering Secret Units.
• Ultra Secret Hunter (1,995 Robux): Greatly increases the chance of pulling Secret Units and stacks with lower-tier hunters.
• Treasure Hunter (479 Robux): Grants 2x luck when opening Secret Chests.
• Instant Craft Unlimited (1,995 Robux): Removes crafting timers completely, useful when crafting raid keys and event components.

Trading for Secret Units

If you do not want to rely entirely on summoning RNG or lengthy Prestige grinds, trading in the trading hub is a reliable alternative:

1. Build Trade Value: Save and fuse duplicate Mythic units (such as Helen the Felon, Man Ray, or Hibernation Sandy) into 5-star units.
2. Collect Shiny and Wombo Variants: Units with "Shiny," "Wombo," or combined "Shiny Wombo" tags hold significantly higher value in the player market.
3. Trade Up: High-tier players and collectors often trade spare secret units (especially Cyborg Plankton or Master Udon) for multiple 5-star mythics, game pass vouchers, or top-tier pets.
4. Untradeable Exceptions: Be aware that certain quest-crafted units, such as the Divine rarity Boys Who Cry band members, cannot be placed into the trading window.

Frequently Asked Questions (FAQ)

What is the easiest secret unit to get in SpongeBob Tower Defense?

Statistically, Master Udon has the highest individual drop rate (1 in 200 from Karate Crates). For banner units, Cyborg Plankton is the most widely owned due to the abundance of gems, with over 100,000 copies in circulation.

Can you get secret units completely free-to-play?

Yes. Gems, Magic Conches, Karate Coins, and Prestige levels can all be farmed through regular gameplay, story clears, achievements, and AFK playtime rewards without spending Robux.

Does the Boosted Banner increase the secret drop rate?

Yes, but only slightly. On the standard banner, Cyborg Plankton has a 0.025% drop rate, while the Boosted Banner raises this chance to 0.03%. The primary benefit of the Boosted Banner is higher odds for Mythic tiers rather than a massive jump for secrets.

Can Divine units like Boys Who Cry be traded?

No. The game prevents quest-line divine units and individual band members from being placed into the trade window. They must be unlocked manually via the mysterious key quest, raids, and the Divine Castle.