Psycho

Type	Enemy
Environment	Solar Eclipse
AI Type	Fighter AI
Damage	70/140/210 (contact); 122245367 (contact while stealthed)
Max Life	550/1100/1650
Defense	40
KB Resist	50%/55%/60%
Banner	Psycho Banner(Desktop, Console and Mobile versions)
Coins	15 SC37 SC50 CC
Hurt	https://terraria.wiki.gg/wiki/File:NPC_Hit_48.wav
Killed	https://terraria.wiki.gg/wiki/File:NPC_Killed_50.wav

Desktop/Console/Mobile-Only Content: This information applies only to the Desktop, Console, and Mobile versions of Terraria.

The Psycho in the stealth state.

The Psycho is a Hardmode, post-Plantera enemy that spawns during the Solar Eclipse event. He will initially spawn in a nearly invisible, stealthed state, waiting for the player to damage him or draw near before he fully reveals himself and starts attacking. The Psycho deals 75% more contact damage while in stealth, similar to the function of the Psycho Knife he drops.

Trivia

The Psycho is a reference to Michael Myers from the 1978 slasher horror film Halloween,^[1] though the sprite more closely resembles Jason Voorhees from the Friday The 13th series.
For some reason, despite following the Fighter AI, the Psycho cannot open doors, nor does he interact with them.

The Bestiary entry for the Psycho: "This masked killer's quiet demeanor and cunning ability to hunt allows him to ambush his victims without being detected."