Swarm. The abomination adds a D4 to its damage for every abomination within a 10 foot radius of the target.

Mass of Flesh. If an abomination is incapacitated within 5 feet of another abomination, it must succeed on a DC 15 Constitution saving throw. If it succeeds it'll merge with the abomination, restoring it 2D4 hit points up to max HP and giving it advantage on strength checks. If it fails the incapacitated abomination immediately dies and cannot be revived.

Bite. Melee Weapon Attack: +2 to hit, reach 5 ft., one creature. Hit: 5 (2D4) piercing damage. 

Claw (Recharge 3-5). Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit: 5 (1D6 + 8) slashing damage. If the abomination rolls a D6 on a recharge, the arm explodes and deals 1D4 damage to the abomination and all creatures in a 5 foot radius.

Grotesque Spittle (Recharge 6). The abomination spits a viscous glob of mucus at a point it can see within 15 feet of it. The glob explodes and each creature within 5 feet of the splash must succeed on a DC 10 Dexterity saving throw or be slowed for 1 minute, on a critical failure the creature takes 1D4 poison damage and is poisoned.