Mantyke living in Galar seem to be somewhat sluggish. The colder waters of the seas in this region may be the cause.
It swims along with a school of Remoraid, and they’ll all fight together to repel attackers.
Though ball-like in shape, this Pokémon is a proficient swimmer. I have discovered that if a Mantyke spends much time with schools of Remoraid, it will eventually achieve evolution.