Black Slaad

Regeneration. The Black Slaad regains 1d10 hit points at the start of its turn if it has at least 1 hit point.

Acid Blood. When a nonmagic weapon that isn’t made of silver hits a Black Slaad that weapon gets a permanent -1 to hit and breaks when it has a -1 to hit. This can be fixed by the mending spell or other magical means. A Black Slaad’s body will be totally disintegrated by its blood when it’s hit points are reduced to 0.

Multiattack. The Black Slaad makes 2 attacks: the Black Slaad makes up to one per action with its sting attack

Reproduction. The Black Slaad attaches a Black Slaad larvae to a humanoid that has 1 or less hit points but is not dead’s face. After one round of combat the target has a Black Slaad tadpole in its body that can only be gotten rid of through the wish spell. The Black Slaad tadpole will eat it’s way out in 2d4 hours killing the host. The Black Slaad tadpole will remain on the face of the target till it is pulled off with a dc15 strength check or it receives 5 damage. All extra damage will be done to the target.

Claw. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d8 + 3) slashing damage. 

Sting. MeleeWeapon Attack: +6 to hit, range 10 ft., one target. Hit: 12 (2d8 + 3) piercing damage, and the target must succeed on a DC 15 constitution saving throw or loose 1d8 hit points each turn and the target is unable to be healed instead the next healing spell will cure this. If this effect would drop the target to below 0 it instead causes the target to go unconscious.