The final boss fight tank

Tank 5-1 is the 21st and final level in the game. Your mission is to defeat the boss (Cyrax), and keep him from eating your pets. After you beat him, you will get Presto the Tadpole and unlock the Challenge Mode. In addition, you will also receive 5000 Shells for destroying him.


5-1 Presto the Tadpole: Presto is a tadpole that can become any other pet you want. However, he recharges in Adventure Mode.

Pets during the battle

All pets appear, except Angie, Brinkley, Nostradamus, Walter, and Stanley (regardless if the player purchases them or not).

Effects of Pets

  • Stinky will hide into his shell every time Cyrax has summoned an alien.
  • Itchy will get angry if Cyrax has summoned an alien. However, Itchy is unable to attack, because these enemies are able to eat him. If Cyrax or one of the aliens is destroyed, Itchy will change his mood.
  • Gumbo's light will activate, but he will not move away from aliens or attract any fish.

Other pets have no effect.


Cyrax - The evil mastermind of the aliens. Cyrax can't damage any of your pets by himself, but he is able to summon all the aliens that you have seem before and mini Sylvesters, smaller and weaker versions of Sylvester. He has the highest amount of health out of any alien, being able to survive a huge quantity of laser shots. He can be very easy if he summons Destructor first, because if he summons Destructor first, all you have to do is destroy his missiles, the mini-Sylvesters and (obviously) Cyrax. If you don't get Destructor first exit the level, then go back into it. Keep doing that until he summons Destructor first.

Mini-Sylvester - A much smaller version of Sylvester. He can be summoned at any time, even when another Alien is present in Tank. To kill it, you need only one shoot, but because of its size and speed, he is able to eat all of your pets if not spotted quickly.

Summoned by Cyrax

  • Sylvester and Balrog are summoned together.
  • Gus has a different manner unlike in Tank 2 to Tank 4. Instead of being immune to lasers, the alien can be damaged with lasers. When he makes contact with a pet, Gus will explode.
  • Destructor is the most recommended alien you must keep him alive to free all your pets. Destroy his missiles, but don't shoot him yet.
  • Psychosquid will not gain his health whenever you shoot him when he turns blue. Psychosquid is a normal enemy.
  • Ulysses is one of the most dangerous aliens in the tank. These energy balls will kill all pets in one hit if redirected in wrong direction and can also damage Cyrax when hit.
  • Bliaterus is another very dangerous alien in the tank. He and Ulysses will destroy many pets. Keep him on the right side of the tank so his bones won't eat the pet and destroy the two heads.


After you beat the final level and defeat Cyrax, you earn 5000 shells and get the ending, which is a credits scene. In there, Angie will revive the pets that have died (if more than 15 pets died, Angie will revive only the first 15). Then, it will show the cast of Insaniquarium (all the fish, pets, and aliens). And then the people who made Insaniquarium. The credits music will play, and after the aliens scroll off the screen, the music changes into a lullaby.

There are 6 possible messages you can get, depending on how many pets have survived:

  • 1-7: No message
  • 8-12: Also, you saved a fair number of pets yourself. Good job!
  • 13-14: Hmmm... actually it looks like not that many pets died. Great work!!
  • 15: Whoa, hold on... Only 3 pets died?! That's incredible! Good shooting, there!
  • 16: Whoa, hold on... Only 2 pets died?! That's incredible! Good shooting, there!
  • 17: My goodness! That's it? You only lost one pet?! That's unbelievable!! How the heck did that happen? You rule this game!!
  • 18: Wait a minute! You didn't lose any pets?! How did you do that? That's really amazing! Seriously though... How did you do that?? Fine, keep it to yourself!

After that message, it will say "Thanks for playing. We'll see you next game".


  • When the aliens, including Mini-Sylvester, kills all the pets, the Game Over dialog box will say "Oops! All of your pets (instead of the word "fish" like other levels) have died!"
  • The death sound of a guppy will play if any of the pets were hit by Destructor's missiles or Ulysses' energy balls. They will simply despawn when this happens because there are no sprites of each pet's corpse.
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