No matter where you go in the Magic: The Gathering multiverse, no matter what magical wonders you may behold or fantastic creatures you may encounter, goblins are always the stupidest creatures on the plane.
Actually, the goblins were one of the smartest, most cunning groups in the Mercadia Block. They run every facet of Mercadia's society, and the human leader is a puppet dictator.
Both lampshaded and subverted in the comical "Unhinged" set, which had five (one per each basic color of Magic: The Gathering) Donkey creatures: Cheap Ass, Smart Ass, Bad Ass, Fat Ass and Dumb Ass. The last one's flavour text reads: "Envying the intelligence of goblins is a bad place to be."
Also, there is always an Ornithopter. Always. One Ornithopter even has a quote stating how every universe has an Ornithopter.
The rules of every edition of Munchkin feature a joke in the set-up rules about how players "start at level 1 with no class". In Munchkin Fu, you start at level 1 "with no class and no style", and later sets start lampshading this with the remark "We never get tired of that joke."