During their colorful history, the A’s have enlisted a mule as a mascot. They have employed a mechanical rabbit to pop out of the ground to deliver baseballs to the home plate umpire. During their short stay in Kansas City, they allowed sheep to graze beyond the right field fence and goats to wander the outfield. (No, not during the game. That would be weird).
One time they endeavored to have a real elephant throw the ceremonial first pitch before a game in Oakland. With its trunk. If memory serves, the pachyderm’s delivery was juuuuust a bit low.