Ketta

Large fiend (shapechanger), neutral evil

Armor Class 17 (natural armor)
Hit Points 136 (16d10 + 48)
Speed 40 ft., burrow 10 ft., swim 30 ft.

STR	DEX	CON	INT	WIS	CHA
21 (+5)	15 (+2)	16 (+3)	13 (+1)	14 (+2)	15 (+2)

Skills Perception +6, Stealth +6
Damage Immunities poison; bludgeoning, piercing, and slashing from nonmagical attacks that aren’t silvered
Condition Immunities poisoned
Senses darkvision 60 ft., passive Perception 16
Languages Common, Infernal
Challenge 10 (5,900 XP)

Special Traits

• Amphibious. The ketta can breathe air and water.
• Shapechanger. The ketta can use its action to polymorph into a cat-humanoid hybrid or into a Large cat, or back into its true form, which is humanoid. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn’t transformed. It reverts to its true form if it dies.
• Keen Hearing and Smell. The ketta has advantage on Wisdom (Perception) checks that rely on hearing or smell.
• Pounce (Cat Form Only). If the ketta moves at least 15 feet straight toward a creature and then hits it with a claw attack on the same turn, that target must succeed on a DC 17 Strength saving throw or be knocked prone. If the target is prone, the ketta can make one rend attack against it as a bonus action.

Actions

• Multiattack (Humanoid or Hybrid Form Only). In humanoid form, the ketta makes two claw attacks. In hybrid form, it can attack twice with its claws and once with its bite.
• Bite (Cat or Hybrid Form Only). Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 10 (1d10 + 5) piercing damage. A humanoid slain by this attack rises 24 hours later as a grendel under the ketta’s control, unless the humanoid is restored to life or its body is destroyed. The ketta can have no more than one Grendel under its control at one time.
• Claw. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 9 (1d8 + 5) slashing damage.
• Rend (Cat Form Only). Melee Weapon Attack: +9 to hit, reach 5 ft., one prone creature. Hit: 23 (4d8 + 5) slashing damage.

About

This enormous, hairless cat glares at you with glowing yellow eyes.

The ketta (she-cat) is considered the “mother” of haugbui in the sense that the creature can create such spawn by inhabiting mounds.

Haugbui Kin. Haugbui are stirred to undead life by a ketta’s presence. They are extraterrestrial demonic forces that animate corpses for their own dark purposes. Ketta have long claws and are even more formidable than haugbui.

Vengeful Souls. Ketta are escaped souls from Helheim; they inhabit a cat which turns monstrous, transforming into something feral and vile that soon seeks solace in grave mounds. Ketta see haugbui they create as their children, and will not hesitate to enact revenge on those who slay their creations.