Space Sharks

Space Sharks are massive mechanical sharks that "swim" around the Ice Planet.

Characteristics
It appears that the space sharks have very few weaknesses, one of which is that they cannot withstand the pull of a Black Hole. Aside from that, the space sharks are also rather slow as compared to your spaceship and will give up chasing you if you fly too far ahead.

Role In Astro-Knights Island
The three space sharks guard Ice Planet, and you cannot land there until the area is rid of them. According to the spaceship databank, the sharks are practically indestructable, so your lasers will not defeat them.You must lure them into the Black Hole in order to destroy them.

Role In Poptropica Adventures for Nintendo DS
Space Sharks made an appearance in a minigame in the Poptropica Adventures for Nintendo DS game. They chase you throughout space on Astro-Knights Island.

Trivia

 * These Space Sharks are similar to Mutant Glump Sharks from Moshi Monsters Season 2 Mission 9: Missing On A Star.
 * Sir Gawain somehow managed to land on the Ice Planet, even though the Space Sharks were probably there when he did so.
 * This is the second time sharks have made an appearance on a Poptropica island, the first time being on Shark Tooth Island.