Brianne Siddall as Thunder / Dylan (voice)

Shanelle Gray as Maggie (voice)

Robin Atkin Downes as Jack / Carlo (voice)

Doug Stone as Mr. Lawrence (voice)

Grant George as Daniel (voice)

Joey Camen as Chihuahua (voice)

Elisa Gabrielli as Carla (voice)

Cinda Adams as Nurse Baxter (voice)

Sage Sommer as Izzy (voice)

Kyle Hebert as Mark Matthews (voice)

Bill Parks as Mike Matthews (voice)

Ella Rouhier as Hospital children (voice)

Noah Ray Strauss as Hospital children (voice)

Isabella Tatone as Hospital children (voice)

Keegan Thomas as Hospital children (voice)

Jim Ward as Reggie (voice)

Susanne Blakeslee as Audrey (voice)

Roxanne Reese as Lasondra (voice)

Joe Ochman as Mr. Eames (voice)

Grey DeLisle as Mrs. Eames (voice)

Lani Minella as Old Lady (voice)

Frank Welker as Cat sounds (archive footage; uncredited)