Hugo

Hugo is a dead ex-raider in Hugo's Hole in 2288

Background
Hugo was a raider with the Dunwich Borers (Fallout 4) but for unknown reasons left, He's found dead in his makeshift shelter past a booby trapped entranced, Next to his body are a few things of interest such as his holotape Dunwich - Hugo's Struggle. Listening to his holotape it's clear that Hugo had gone insane and talks of a thing he calls an 'it' and in the end of the holotape he says it's "Time for him to sleep, It's loaded (His 10mm Pistol)" and kills himself.

Appearances
Hugo appears only in Fallout 4.

Behind the Scenes
The nearby Dunwich Borers (Fallout 4) and Hugo's tape are both Lovecraftian references to Lovecraft's "The Dunwich Horror".
 * The being he refers to is probably one of the great old ones I.E. Cthulhu who turns people insane by simply seeing him.