Clay Golem Converter

Acid Absorption. Whenever the converter is subjected to acid damage, it takes no damage and instead regains a number of hit points equal to the acid damage dealt.

Amorphous. The converter can move through a space as narrow as 1 inch wide without squeezing.

Immutable Form. The converter is immune to any spell or effect that would alter its form.

Magic Resistance. The converter has advantage on saving throws against spells and other magical effects.

Spider Climb. The converter can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Multiattack. The converter makes two pseudopod attacks. If both attacks hit a Medium or smaller humanoid, the target is grappled (escape DC 16), and the converter uses its Smother on it.

Pseudopod. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) bludgeoning damage plus 9 (2d8) acid damage. If the target is a creature, it must succeed on a DC 16 Constitution saving throw or have its hit point maximum reduced by an amount equal to the acid damage taken. The target dies if this attack reduces its hit point maximum to 0. The reduction lasts until removed by the greater restoration spell or other magic.

Smother. The converter smothers a medium or smaller humanoid grappled by it. The smothered creature can't breathe, is restrained, and it must succeed a DC 16 Constitution saving throw at the start of each of the converter's turns or take 27 (6d8) acid damage. If the converter moves, the smothered target moves with it. The converter can only have one creature smothered at a time.

Conversion. The converter targets a medium or smaller humanoid within 10 feet of it that has been dead no longer than 1 minute and was killed by the converter's smother. The converter transforms the target into a clay golem over the course of 1 minute unless it loses concentration (as if it were concentrating on a spell). If the converter loses concentration then the conversion fails otherwise, the target rises as a clay golem under the converter's creator's control. After every successful conversion, the converter's size is decreased by one category and, when the converter's size category is small, it dies after the next successful conversion. 

Liquefy (Recharge 5-6). Until the end of its next turn, the converter gains a +2 bonus to its AC, has advantage on Dexterity saving throws, and its speed increases by 20 feet.