Le Squish was an alias of SpongeBob in the episode "Demolition Doofus." SpongeBob received the name from Captain Lutefish, after being a very tiny size, but able to compete in the derby.
Le Squish rides in a very tiny boat with the number two, and he wears a sock.
When Mrs. Puff
puts SpongeBob in the Derby, Captain Lutefish is unsure. After seeing what he can do, Captain Lutefish puts his sock over SpongeBob and inserts him into the derby.