Countdown Croc

Countdown. When the countdown croc hits a creature with its bite attack, the target becomes “marked” and the croc gets a timer of 1d6 + 2. The croc then gains advantage on all attacks against its marked target. Every time the croc hits its marked target with its bite attack, the timer counts down by one. When it reaches 0, if the target is a large or smaller creature, it is immediately swallowed. The mark remains until either the target or the countdown croc die. The countdown croc can only have one marked target at a time.

A swallowed target is blinded and restrained, it has total cover against attacks and other effects outside the countdown croc, and it takes 44 (8d10) bludgeoning damage at the start of each of the croc's turns. The croc can have only one target swallowed at a time. If the croc dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 5 feet of movement, exiting prone.

Maddening Tick. Whenever a marked target starts its turn within 60 feet of and can hear the countdown croc, the target must succeed on a DC 20 wisdom saving throw or become frightened by the countdown croc. The DC for this saving throw decreases by 1 for each number left on the timer. If the target can no longer hear or see the countdown croc at the start of its turn, it can repeat the saving throw, ending the effect on a success.

Clockwork Body The countdown croc emits a constant ticking. It has disadvantage on all Dexterity (Stealth) checks.

Heart of a Beast The countdown croc is also considered to be a beast for the purposes of spells and effects.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) piercing damage, and if the target is a large or smaller creature, it is grappled by the countdown croc (escape DC 15)

Slam. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 21 (3d10 + 5) bludgeoning damage. If the countdown croc is grappling a target when it uses this attack, the grappled target takes 10 (3d6) bludgeoning damage as well.