Anthony Michael Hall as Gary

Kelly LeBrock as Lisa

Ilan Mitchell-Smith as Wyatt

Bill Paxton as Chet

Suzanne Snyder as Deb

Judie Aronson as Hilly

Robert Downey Jr. as Ian

Robert Rusler as Max

Vernon Wells as Lord General

Britt Leach as Al

Barbara Lang as Lucy

Michael Berryman as Mutant Biker

Ivor Barry as Henry

Ann Coyle as Carmen

Suzy J. Kellems as Gymnast

John Kapelos as Kandy Bar Owner

Fred D. Scott as Bar Patron

Vince Townsend Jr. as Bar Patron

Chino 'Fats' Williams as Bar Patron

Jill Whitlow as Perfume Salesgirl

Theodocia Goodrich as Lingerie Saleswoman

Wallace Langham as The Weenies

Johnny Timko as The Weenies

Mikul Robins as The Weenies

Darren Harris as The Weenies

Renee Props as The Weenies

Michael Cramer as The Weenies

D'Mitch Davis as Bartender

Mary Steelsmith as Girl in Bathroom

Robin Frohman as Girl in Bathroom

Alison Carole Lowe as Girl in Upside Down Bathroom

Kym Malin as Girl Playing Piano

Jennifer Balgobin as Biker Girl

Jeff Jensen as Metal Face

Prince Hughes as Party Guest

Rick LeFevour as Policeman

Rock A. Walker as Policeman

Joe Gieb as Blob Operator

Kevin Thompson as Blob Operator

Doug MacHugh as Wyatt's Father

Pamela Gordon as Wyatt's Mother

James Huffman as Young Kid at Party (uncredited)

Steve James as Guy at Table (uncredited)

Michael K. Washko as Mall Shopper (uncredited)

Todd Hoffman as The Weenies