The Zyzaks are the villains from the Oscar-winning short film The Chubbchubbs and are voiced by Peter Lurie.
The Zyzaks are thuggish and huge, ogre-like aliens who spout lightning from their weapons who are also the monsters responsible for the deaths of Meeper's parents: when Meeper tries to warn the other aliens about the Chubbchubbs approaching, they won't listen until another alien does so.
The aliens run away except Meeper, who discovers little yellow fuzzballs and hides them in his janitor's bucket but the Zyzaks approach them and Meeper begs them to be friends with him. As he dances and sings, Meeper trips over his bucket, releasing the fuzzballs so the Zyzaks aim their weapons at them when fuzzballs bare their ragged fangs and growl - with that, the Zyzaks back up in terror and shriek "IT'S THE CHUBBCHUBBS!!!": sure enough, the Chubbchubs stand their ground and pounce on the Zyzaks, consuming them from head to toe as the last Zyzak cries out "Mommy!" before being devoured by the Chubbchubbs.