Rahab (Hebrew רַהַב, Rahab) is a chaos-monster of the deep in the Hebrew Bible — not the woman of Joshua 2, which is a different Hebrew word entirely. God "cut Rahab in pieces" and "pierced the dragon" in Isaiah 51:9; "stilled the sea" and "shattered Rahab like a corpse" in Psalm 89:10; Job 26:12 again invokes God's defeat of Rahab at the founding of the cosmos. Named alongside Leviathan, Rahab is one of the clearest surviving fragments of Chaoskampf in the Hebrew Bible — the older mythological combat with the sea-monster that Genesis 1 worked to suppress but never fully erased from the poetic and prophetic books.
The ancient Near Eastern combat motif Rahab is a clear Hebrew surviving fragment of.
The other Hebrew sea-serpent — named alongside Rahab as the chaos God subdues.
The Babylonian saltwater goddess slain by Marduk — the eastern cousin of the same sea-monster pattern.
Reading Genesis 1 slowly, with the surviving chaos-monster traces in the rest of the Hebrew Bible in view.