Vortexian

The Vortexian is a Hardmode, post-Lunatic Cultist enemy spawned by the Vortex Pillar during the Lunar Events. Their death opens a portal that shoots lightning bolts similar to one of the attacks of the Lunatic Cultist. They are powerful in packs, and can potentially start an overwhelming lightning chain reaction if not dealt with properly.

Trivia

 * They seem to resemble the Moon Lord with legs, but without the eyes or the spine. The teardrop design on its chest, combined with the exposed brain further supports this.