Endlessly reconstitutes after defeat

Apep

Crucially, in most tellings Apep is never permanently destroyed, only cut down, repelled, or driven off night after night, only to reconstitute himself and renew the assault the following night;

Walutahanga

The core episode is a cycle of destruction and restoration: Walutahanga is repeatedly cut apart or killed by relatives who fear or resent her serpent form, and each time restores herself, so that the attempts against her fail cumulatively rather than singly.