Corrupted Rat Brute
Medium beast, chaotic evil
Hit Points: 52 (8d8 + 16)
Armor Class: 13 (natural armor)
Speed: 40 ft., climb 30 ft.
Abilities
Str 16 (+3), Dex 14 (+2), Con 15 (+2), Int 3 (-4), Wis 12 (+1), Cha 4 (-3)
Skills: Perception +3
Senses: Darkvision 60ft., passive Perception 13
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 3) piercing damage.
Corrupted Hadar Frenzy (Recharge 5-6). The Mutated Rat Brute goes into a frenzy, allowing it to make two bite attacks as a bonus action for its next turn.