Batibat
The batibat is a vengeful tree-dwelling hag of Ilocano folklore, an obese female spirit who, when her tree is felled for a house post, migrates into it and sits on the chests of sleepers to suffocate them with fatal nightmares (bangungot). Biting one's thumb or wiggling the toes breaks her grip; the belief explains sudden unexplained nocturnal death syndrome.