Scooby-Doo and the Alien Invaders

Third entry in the Scooby-Doo canon, featuring aliens from outer space.

Tropes
Aliens Are Bastards: The movie seemingly plays this straight, but it ultimately averts it. It turns out that the aliens that are evil are actually humans and that Crystal and Amber are aliens though they're actually good.

Distaff Counterpart: Though she's technically from outer space, it's noted that Crystal and Shaggy are a LOT alike. The same applies to her dog Amber though she's technically an alien too though she's a more animalistic alien than Scooby. It turns out that like Scooby, she's capable of speech, though it's more coherent.

Humans Are the Real Monsters: The evil aliens turn out to actually be human. The actual aliens are rather innocent.

Innocent Aliens: Crystal and Amber both turn out to be this.

Statuesque Stunner: Shaggy notes that during his love song about Crystal that she is rather tall. Technically, they're about the same height.