Resident leper

Another creature dwells down here, the one certainly to fear
He stays below both day and night
Never does he see the light

Long ago he used to do the show
But his fragile mind degraded with time
Slipping under, never to return
A glance over his shoulder, then he was gone

Now he's become the Resident Leper
Nothing left but a decrepit cretin
Stalking the tunnels with voracious hunger
Leprous, lecherous, down in his lair it's treacherous