Escorting Beakworm

The Escorting Beakworm evolved from the Multicolor Beakworm. Unlike its ancestor it doesn't live in shoals, but follows big creatures like the strainbean and the snark. They remove all parasites, like the strainbeansuckers and keep the skin clean. In return they're safe and won't be eaten by its host and they can eat the rests, which the host lets fall down. No matter where they are on the skin, their top is always directed to their host, so that they can pick things with their bended beak from the skin. In conclusion the fin at the top degenerated, while the fins at the bottom became larger.