They slowly swim up to Boats, jump on it and drill a hole in 3 seconds, resulting in a boat leak that drains 1 /s.
They are neutral towards the player. If attacked, they will fight back, delaying the drilling process during the time of the fight. If they are killed before the end of the drilling, no leak is formed.
After drilling they go back into the water and stay neutral for 30 seconds. They take 90 seconds to respawn.
They will feed on Logs, Boards, Twigs, and Living Logs left in the water, leaping out of the water and eating one item per jump. They seem to prioritize items left in the water over boats.