To impress a beautiful girl, Harold Kelp, the grandson of professor Julius Kelp, who created a potion to transform his personality, gets his hands on his grandfather's secret elixir and unleashes his destructive alter ego, Jack.
Drake Bell
as Harold Kelp/Jack Love
Jerry Lewis
as Professor Julius Kelp / Buddy Love
Tabitha St. Germain
as Robin
Logan McPherson
as Zeke/Waiter/Fear/Ned
Jarrod Young
as Begews
Brian Drummond
as Dean Von Wu
Andrew Francis
as Brad/Tad
Britt Irvin
as Polly
Danielle Lewis
as Suzy Perkins
