Shediac is a grayish-blue supply shed that Theodore met while he was at the repair dock. He, along with Hank, supply bumpers to the Big Harbour. Shediac also gives Sigrid a special green bumper in Sigrid and the Bumpers. He first appears in the fourth season episode, Theodore Lands On Earth.
- Season 4 - Theodore Lands On Earth, Sigrid and the Bumpers, Hank's Wheezy Whistle (cameo), Rebecca and the Big Snore (cameo), Nautilus and the Sinking Ship (cameo), and Emily's Bruised Bumper (cameo)
- Season 5 - Hank Hurts a Ship (cameo), Theodore and the Harbour Crane (cameo), Hank Stays Up Late, Theodore the Tattletug (cameo), George and the Flags (cameo), Hank Stays Up Late, Hank's Cozy Cove (cameo), Theodore and the Hunt for Northumberland (cameo), Bedford's Big Move (does not speak), Guysborough Makes a Friend, Pugwash is Gone! (cameo), Foduck and the Shy Ship (cameo), George Waits His Turn and Theodore's Big Decision (cameo)
- He is named after the town of Shediac in New Brunswick.
- He speaks with a Down East (Maine) accent.
- In various episodes Shediac has been put in the wrong place rather than his dock.