Walk Without Rhythm

Summon with a Mechanical Worm (or wait - the mechs spawn naturally at night until beaten). The Destroyer is one long segmented worm plus a swarm of probes: build a sky bridge or box, and bring piercing or area damage - jester arrows early, or the Daedalus Stormbow raining holy arrows melts it embarrassingly fast. The probes drop hearts, which is your sustain. Souls of Might from the carcass build the Megashark.