>>71976974The Reef Shark is an extremely weak enemy with a Challenge Rating of only 1/2 and nothing notable beyond Pack Tactics
The Hunter Shark is a slighly stronger enemy at CR 2 with Blood Frenzy rather than Pact Tactics, making it fairly dangerous for low level parties but still a smallfry for experienced parties
Lastly the Giant Shark is a CR 5 enemy with triple the health of the Hunter Shark and faster by 10 feet but otherwise an identical clone, making it very dangerous for low level parties, a fair challenge for parties approaching mid levels, but still overall a weak enemy when compared to all other monsters in the bestiary.