Pirate Deckhand

The deckhand exists only while a Pirate Invasion is running. It cannot spawn on its own and nothing summons it directly, so the event is the only thing that puts one in your world, and the survivors leave when the event ends.

It runs at you and jumps. That is the entire behavior. A low wall does nothing, since the jump clears it, but it has no ranged option at all, so height beats it outright. A platform a few tiles up with open air underneath leaves the deckhands milling around below while you handle the pirates that can actually shoot back.

It is the filler body of the invasion, which quietly makes it the source of a large share of what the event hands out, including the golden furniture, the Buccaneer vanity and the Barrel Launcher added in later versions. None of it is likely on any one kill. Running whole invasions beats camping a single enemy type, since finishing the event and starting another is faster than waiting on a roll from these.