The creature of the cosmos is the titular being of a film that Burt puts on in Drive-In Me Crazy who comes to life after Swamp Beast. Emerging in a flying saucer, it zaps Harley with a red energy beam, melting his bike and leaving him smoking.
It turns out to be a purple (darker shade than Kat) tentacled creature which Coop calls "squid-face". It is able to fire green rays from its eye that puts holes in buildings and can set the Swamp Beast on fire.
It is eventually absorbed by the Glob.