Adaptive Resilience. SCP-682 gains resistance to a damage type after taking a total of 20 damage from that type. After taking an additional 10 damage of the same type, SCP-682 becomes immune to it.

Multi Attack SCP-682 makes two attacks: one with its bite and one with its tail. Or 2 claw attacks.

Claw melee weapon attack: +5 to hit range 5 ft. 6 (2d4+2) target must succeed a DC 12 constitution saving throw or receive the bleeding condition (take 3[1d6] damage at the start of they're turn. to get rid of bleed condition an ally must perform a DC 10 medicine check or player must healed for however much damage was revived by the claws 6[2d4+2])

Bite. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 10 (2d6 + 4) piercing damage.

Tail Swipe. Melee Weapon Attack: +6 to hit, reach 15 ft., one target. Hit: 12 (2d8+ 4) bludgeoning damage. On a hit, the target must succeed on a DC 16 Strength saving throw or be knocked prone.

Acidic Spray (Recharge 5-6). SCP-682 exhales a 30-foot cone of corrosive acid. Each creature in that area must make a DC 15 Dexterity saving throw, taking 20 (7d6) acid damage on a failed save, or half as much damage on a successful one.

Regenerative Feast. When SCP-682 consumes a corpse or defeated creature as a action, it regains 30 hit points. SCP-682 can use this ability once per round.

Swallow Whole. If SCP-682 hits a Medium or smaller creature with its bite attack, the target is grappled (escape DC 14) and swallowed. The swallowed creature is blinded and restrained, it has total cover against attacks and other effects outside SCP-682, and it takes 9 (3d6) acid damage at the start of each of SCP-682's turns. If SCP-682 takes 20 or more damage on a single turn from a creature inside it, SCP-682 must succeed on a DC 17 Constitution saving throw at the end of that turn or regurgitate the swallowed creature, which falls prone in a space within 10 feet of SCP-682.

Opportunity attack

Legendary Resistance (3/Day). If SCP-682 fails a saving throw, it can choose to succeed instead. 

SCP-682 can take 2 legendary actions, using the adaptive strike option below. It can take only one legendary action at a time and only at the end of another creature's turn . Scp-682 regains spent legendary actions at the start of its turn.

Adaptive Strike. SCP-682 chooses a damage type that it's immune to and makes one bite attack. This attack deals an additional 2d6 damage of the chosen type.