Jack Black guy

There’s a Celtics regular who looks like Jack Black and he’s another Jumbotron favorite.

He’s even got his own prerecorded video clip that aired during Game 5 that features him talking to a mirror where images of Jack Black pulled from “School of Rock” make up a conversation to build the fan’s confidence for dancing during timeouts.

He seems to have free reign of the building at times and, yes, there’s even a YouTube video of him.

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