Garth Sinew is the strong bodybuilding P.E. teacher at Walkerville Elementary. He only appears in "Works Out" as Ms. Frizzle's toughest competition in the Teacherathalon, and the episode's main antagonist.
- He was voiced by NFL Hall of Fame quarterback Dan Marino of the Miami Dolphins.
* Debut | ** On TV | *** In the Movie |
* Debut | ** Briefly |