- The Mega Crab is a special event that involves Dr. T and his super weapon.
- The Mega Crab is a large base with infinite stages on top of a large, purple, mechanical crab near the player's home base.
- It is not a part of the regular Event Cycle. The Mega Crab appears once per month, starting at 6pm the player's local time, usually on the last Friday of the month, and ending on midnight the following Sunday night.
- The Mega Crab is an enormous purple crab-like machine created by Dr. T as his weapon of mass destruction.
- It has 6 legs, 3 on each side, powered by heavy hydraulic engines.
- It has 3 large, red eyes on the front and two huge claws.
- Its left claw has a grey drill while its right claw has a clamp.
- There are two giant containers on its back with nuclear symbols. They seem to be nuclear reactors that power the Mega Crab.
- The Mega Crab has an infinite amount of stages. Each stage is unlocked as the previous one is defeated.
- Between stages, different parts of the floor will raise or lower. This changes the shape of the battlefield for each stage.
- Stages can contain all regular Defensive Buildings and all Prototype Defenses.
- Each stage of the Mega Crab generally has more powerful Defensive Buildings and Ice Statue boosts than the previous one.
- To beat a stage, you must destroy the Mega Core.
- The Mega Crab can only be attacked if the player has attacks remaining.
- The player is provided with a number of attacks at the beginning of a Mega Crab event.
- Attacks may be given after a certain period of time has elapsed. However (particularly in the cases where large numbers of attacks are given), it is possible for there to be no regeneration of attacks.
- Different Mega Crabs have different numbers of maximum attacks. For instance, some have a maximum of 6 attacks while more recent crabs, like the Beastly Crab, have a maximum of 40 attacks.
- One free attack is given upon the completion of any stage.
- A number of buildings appear only on the Mega Crab and cannot appear outside of it (or its spinoff, the Mega Turtle).
- Of these buildings, only the Critter Container and Cryo Bomb below make regular appearances on Mega Crabs. Others may nonetheless make appearances in some Mega Crabs, depending on its theme; for example, the Super Warrior Vat appeared on the Tribal Crab.
- When a Critter Container is broken, it releases 9 friendly Critters that attack the enemy buildings regardless of player's own Critters level.
- A special variant of the Critter Container is present for Mega Crab Events near Halloween. When broken, it releases 9 friendly bat-like critters that behave like regular Critters, except for the fact that they do not trigger any type of Mines (however, they can still be affected by explosions of said Mines).
- Each Critter Container has 270 health.
- When a Cryo Bomb is triggered by its health being reduced to zero and after a 2 second delay, it releases a large icy blast that freezes troops and buildings around it and sets off mines.
- The freeze effect lasts for 20 seconds and reduces attack and movement speed by 75%.
- Each Cryo Bomb has 270 health and its blast does 260 damage.
- When a Speed Serum is triggered by its health being reduced to zero, after a short delay, it releases a pink blast that increases the speed of all troops and buildings around it. Unlike the Cryo Bomb, it does not trigger Mines.
- Each Speed Serum has 500 health.
- The Scary Mortar is a special defense appearing in Mega Crab Events near Halloween. It does low damage, but it releases a pumpkin-shaped shell that confuses troops and Critters upon impact, making them wander off erratically for a few seconds. Affected troops will not respond to Flares. The impact is accompanied by menacing laughter.
- Each Scary Mortar has 6,000 health and does 5 damage per second.
Dr. T Lookalike
- The Dr. T Lookalike is a cardboard cutout of Dr. T standing on a wooden box with a purple speaker, occupying a 2x2 space. When troops are in its range, audio of Dr. T's taunt will play, drawing in nearby troops.
- Each Dr. T Lookalike has 1,400 health and does 1 damage per second. When destroyed, it does 400 damage in a small radius.
Super Soldier Vats
- The Super Soldier Vats refer to multiple different types of vats, that are named according to the troop that they hold inside them. Each of these vats contains a very powerful version of a specific troop, which will fight for you.
- The vats vary in contents and hence vary in names. They even vary in hitpoints.
- The troops contained inside them behave like Critters and will not follow Flares, will not be buffed by Magma Statues of any sort, and cannot be healed by the Medkit or by Medics. They also do not count towards casualties if they are destroyed.
- The troops contained inside these vats include:
- A Rifleman, released from a Rifleman Vat, which has 10,000 health.
- A Heavy, released from a Heavy Vat, which has 20,000 health.
- A Warrior, released from a Warrior Vat, which has 20,000 health.
- A Medic, released from a Medic Vat, which has 15,000 health.
- A Grenadier, released from a Grenadier Vat, which has 15,000 health.
- A Critter Bat, released from a Critter Vat, which has 20,000 health.
- Some troops have a set of passive abilities that are not normally available to the player.
- Riflemen have a greatly increased firing rate, similar to a Machine Gun.
- Warriors freeze buildings they hit in a similar manner to the Cryoneer.
- Medics will also speed up troops, with a similar effect to Speed Serum.
- Grenadiers throw five grenades per volley, each causing a big blast.
- When you defeat a Mega Crab stage, you will be rewarded with Resources and Power Stones from the normal chance.
- You also have a chance of earning other items including:
- Starting from the March 2018 Mega Crab, reaching certain stages will reward the player with exclusive trophies, which is gifted by the Trader and can be claimed from the Decorations tab in the player's inventory.
- The update that Mega Crab came out in was called "The Last Crustacean".
- On the archipelago, the Mega-Crab's body is completely purple. However, when scouting, its back is open, filled with greyish-purple platforms and swaths of green liquid.
- Although the Mega Crab occasionally drills at an island, it does not appear to damage the island at all.
- The first event started on January 15, 2016 at 6 PM the player's local time and lasted for 7 days. The second one began March 25, 2016 - this one lasting only three days. The third one started July 1, 2016 and also lasted for 3 days. The fourth event started on October 28, 2016 and lasted for 4 days. The fifth event started on January 27, 2017 and lasted for 5 days and 4 hours. The sixth started on May 26, 2017 and lasted for 3 days. After the March 2018 update, the Mega Crab event became a monthly occurrence.
Note: in some Events, the Wood, Stone and Iron rewards are not the same order as in the table.