Hold Breath: The crocodile can hold its breath for 15 minutes.
Bite: Melee Weapon Attack:+4 to hit, reach 5 ft., one creature.
Hit:7 (1d10 + 2) piercing damage, and the target is grappled (escape DC 12). Until this grapple ends, the target is restrained, and the crocodile can't bite another target.
Hold Breath: While out of water, the octopus can hold its breath for 1 hour.
Underwater Camouflage: The octopus has advantage on Dexterity (Stealth) checks made while underwater.
Water Breathing: The octopus can breathe only underwater.,
Tentacles: Melee Weapon Attack: +5 to hit, reach 15 ft., one target.
Hit: 10 (2d6 + 3) bludgeoning damage. If the target is a creature, it is grappled (escape DC 16). Until this grapple ends, the target is restrained, and the octopus can't use its tentacles on another target.
Ink Cloud (Recharges after a Short or Long Rest): A 20-foot-radius cloud of ink extends all around the octopus if it is underwater. The area is heavily obscured for 1 minute, although a significant current can disperse the ink. After releasing the ink, the octopus can use the Dash action as a bonus action.
Pack Tactics: The shark has advantage on an attack roll against a creature if at least one of the shark's allies is within 5 feet of the creature and the ally isn't incapacitated.
Water Breathing: The shark can breathe only underwater.,
Bite: Melee Weapon Attack: +4 to hit, reach 5 ft., one target.
Hit: 6 (1d8 + 2) piercing damage.
Amphibious: The toad can breathe air and water.
Standing Leap: The toad's long jump is up to 20 feet and its high jump is up to 10 feet, with or without a running start.,
Bite: Melee Weapon Attack: +4 to hit, reach 5 ft., one target.
Hit: 7 (1d10 + 2) piercing damage plus 5 (1d10) poison damage, and the target is grappled (escape DC 13). Until this grapple ends, the target is restrained, and the toad can't bite another target.
Swallow: The toad makes one bite attack against a Medium or smaller target it is grappling. If the attack hits, the target is swallowed, and the grapple ends. The swallowed target is blinded and restrained, it has total cover against attacks and other effects outside the toad, and it takes 10 (3d6) acid damage at the start of each of the toad's turns. The toad can have only one target swallowed at a time. If the toad dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 5 feet of movement, exiting prone.
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Bite: Melee Weapon Attack: +5 to hit, reach 5 ft., one target.
Hit: 10 (2d6 + 3) piercing damage.
Bonus Action Rampage: When the hyena reduces a creature to 0 hit points with a melee attack on its turn, the hyena can take a bonus action to move up to half its speed and make a bite attack.