Araripesuchus wegeneri (Dog Croc)

Pack Tactics: The Dog Croc has advantage on an attack roll against a creature if at least one of it's allies is within 5 ft. of the creature and the ally isn't incapacitated.

Big bites: If the Dog Croc uses bite on a tiny creature and crits, the creature is swallowed whole.

The power of love/Hormones: If it is mating season a nat 1 crits too. Its armor class increases by 1. Its speed increases by 5ft.

Lair:

HELP: When a baby Dog Croc is at the nest it can use a bonus action to call for help. If its father or mother is not already killed it will appear after 1 Round.

Mothers senses: If a female Dog Croc is at its nest it gets a +2 to Perception.

Bite: Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 10d6 + 15 piercing damage. If the target is a creature of tiny, small or medium size, it must succeed on a DC 11 Strength saving throw or be grappled.

If the target is grappled, the Dog Croc can't take a Bite action, as it uses its mouth to grapple it.

Not my baby: If a female dog Croc protects its baby, usually at its nest, it can take a bonus action to attack. It can only use an attack it hasn't used this turn. (E.G.: Used Bite as an action, then Bonus action with claw attack)

RAGE!: If the baby or the female is killed while the male is still alive, it enters a rage state which allows it take a bonus action to attack. It can only use an attack it hasn't used this turn. (E.G.: Used Bite as an action, then Bonus action with claw attack)

Tail tactic: If a creature moves behind the Dog Croc, it can use a reaction to use its tail to kick them off their feet. The creature must succede on a 13DC Dexterity saving trow or be knocked prone.