Cryptosporidium

Crypto is the main antagonist and playable character in the sci-fi/comedy video game Destroy All Humans! along with its sequels: he is actually one of many clones and exists to harvest human DNA in order to ensure the survival of his own species - throughout the game he is given increasing levels of power and ultimately ends up becoming the new President.

The game is set in the 1950s and parodies the Cold War era hysteria as well as B-Movies: in fact when Crypto is spotted by certain humans they call him a "commie" - suggesting that despite his hideous appearance these people actually believe his is a Communist rather than an alien.

Crypto is a genius but also a very comical character in the fact he has little real knowledge on humanity - although he is quick to express his dislike of them, which is not really surprising considering he is part of a warlike species who are already in possession of advanced weaponry sufficient to destroy entire cities.

As Crypto the player has an arsenal of such weaponry to utilise against the humans (both innocents as well as such enemies as the military and Men In Black) - when his weapons fail him Crypto can enter his large flying-saucer and use it to destroy anything in his path: though the more mayhem Crypto causes the more humanity will fight back and alert more powerful enemies to his location.