Finn, the very good boy, is a bat dog for the Oakland A's Triple-A affiliate, the Las Vegas Aviators.
Finn was trying to do his job on Tuesday night in the Aviators' game against the Sacramento Rivercats, but ... the home-plate umpire happened to grab the bat first. The crowd let him know how they felt about his jerkwad behavior....and it just might be the loudest boo for an umpire in the history of baseball!
WATCH BELOW!