- Classification: Kaijū
- Homeland: Planet Acrobat
- First Appearance: Manga Chapter 1, Anime Episode 3
Acrobat-seijin (アクロバット星人, Acrobat Alien) is an acrobat Kaijuu who first appears in the first serialized chapter as one of the invading aliens. Kinnikuman claims the best defense against his acrobatic moves is finger pops. A character resembling Acrobat-seijin appears in Kinnikuman Nisei: Ultimate Choujin Tag Arc among the pile of tag teams killed by the Time Choujins, but it is unknown whether or not it is him.