'Eaten Alive' aka 'Death Trap' (1975) – Tobe Hooper.

Lurking somewhere deep within the swelteringly sinister swamps lies the insanely inhospitable 'Starlight Hotel', this diabolically death-dealing domicile being morosely run by the maniacal misfit Judd (Neville Brand), a persistently poisonous proprietor perversely providing inexorable doom in each and every room, wherein the guileless guest cannot refuse the generous harms, and is gruesomely guaranteed to rest in pieces, whether by skull-shattering scythe, or flesh-shredding maw of a distempered lake dwelling B-Movie behemoth, in this woefully misbegotten dive y'all be 'Eaten Alive' by an uncommon fear, with terror-ific turns from lurid legends Neville Brand, Robert England, Carolyn Jones, and a sublimely sensuous starlit performance from bodaciously buxom scream dream Janus Blyth! Macabre maestro Tobe Hooper's outrageously hostile hostel proves to be a horrific host to a kaleidoscopic calamity of heinous, flesh-flaying horrors, thereby guaranteeing a hot and cold running bloodbath in each room!