Alien

Fallout Tokens

Doctor Who Tokens

Adipose Offspring

Emerge {5}{W} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When Adipose Offspring enters, create a 2/2 white Alien creature token. If Adipose Offspring's emerge cost was paid, instead create X of those tokens, where X is the sacrificed creature's toughness.

New New York

At the beginning of combat on your turn, until end of turn, noncreature artifacts you control become 3/3 Vehicles in addition to their other types and gain flying, haste, and crew 1.
Whenever chaos ensues, create a Treasure token and a 2/2 white Alien creature token.

North Pole Research Base

At the beginning of your upkeep, target opponent draws a card and creates a Treasure token.
Whenever chaos ensues, create a 2/2 white Alien creature token. When you do, tap target nontoken creature an opponent controls. Put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)