Derpling

Hardmode only, on the jungle surface, and only in daylight. It takes the day shift from the Giant Flying Fox, which works the same ground at night. Nothing summons it and there is no event attached.

The whole attack is one long leap. It springs well over your head, corrects sideways in midair, and tries to land on the tile you are standing on. Holding still to line up a shot is exactly how you eat the hit. Keep walking sideways and it comes down behind you every time. The danger is the count rather than the individual: they spawn quickly, and a short walk turns into four or five arriving from different heights. Kill each one as it lands instead of letting a group build up around you.

It shares both its behavior and its silly name with the Herpling, the pair of them taken from the phrase herp derp.