15 mm scale
"Sorry to interrupt your recreation, fellows, but it is time for Sgt. Pinback to feed the alien."
John Carpenter's 1974 film, "Dark Star", is a weird, fun, low-budget story about a cranky crew of oddballs dealing with life in space and trying to save themselves from an intelligent bomb that has decided it wants to explode. A major subplot features the shenanigans of a maliciously mischievous beachball-shaped alien (obviously made from... a beachball, and a pair of Halloween fright hands) which wreaks havoc on the ship while moving around via the ventilation ducts.
Dark Star was co-written by (and co-starred) Dan O'Bannon, who went on to write a rather more well-known 1979 film about a cranky crew of oddballs whose spaceship was destined to self-destruct, confronting a malicious alien traveling through the ventilation ducts:
|"Look, we have actual money now!"|