Transformers: Animated Season 1 Episode 10
Megatron creates Soundwave, a robot in the form of a toy robot for Isaac to give to Sari for her birthday. Bulkhead is the only one who finds the toy to be a bad thing and finds out that the toy is evil. Unknown to Sari, the more she uses her key on Soundwave, the more he will evolve into a bigger robot.
Serie: Transformers: Animated
Episode Title: Sound and Fury
Air Date: 2008-02-23