Even with a myriad of fan artwork depicting firbolgs as large, blue, cow people, There's little in the way of official lore that covers what firbolgs look like. We do know that They are really large, generally coming in at over 7 feet tall and 300 lbs. ability granted by https://triton-dnd81346.ltfblog.com/27258444/detailed-notes-on-tiefling-mage