Probably The Specials (2000). From the early scriptwriting days of James Gunn (you know, the guy who directed both Guardians of the Galaxy movies).
From IMDb (formatted a bit for the sake of readibility):
The Specials, the sixth or seventh greatest superhero group in the world, count the geeks and the oddballs among their fans. They don't have the prestige or the money that a group like the Crusaders has. But they've found their niche as the Ringo Starr of superhero teams.
- There's the Weevil, the most popular member and the one pursued by other teams;
- the blue-skinned, foul-mouthed Amok;
- Minute (My-noot) Man, who is sensitive about his oft-mispronounced name;
- the ever-sneering Deadly Girl;
- the naive and boyish U.S. Bill;
- the Strobe, the leader of the team;
- the Strobe's wife, Ms. Indestructible, who is having an affair with the Weevil;
- the irritatingly perky Power Chick;
- the green-skinned weirdo, Alien Orphan;
- the fat and pompous Mr. Smart;
- and Eight, who has eight different bodies.
The new member is a longtime fan who calls herself Nightbird. Unfortunately, she joins just when Cosgrove Toys creates a new line of action figures based on the Specials. The company's disastrous press conference could mean the end to this cut-rate super-group.
"Eight" replicas have black shirts with white numbers. Image courtesy of this review introducing all the "Specials", and mentioning 8 Bodies with a Single Consciousness & Group Intelligence as one of Eight's clichés.
Found with the Google query movie alien "eight * bodies"
which returned this website.