Ice Mephit (Rainbowland Variant)

Sorcerer-Bound Statistics. The Mephit's Armor Class equals 11 + half the summoning Sorcerer's Sorcerer level (rounded down). Its Hit Points equal 20 + 5 times half that Sorcerer level (rounded down).

Icy Replication. Each of these independently creates one full-HP replica: (1) this Mephit scores a Critical Hit with Rend; (2) a creature rolls a natural 1 on its Frost Burn save, even if it succeeds. Both can occur on one hit, creating two replicas. Place each in an unoccupied space within 5 ft. of its parent; otherwise that replication fails. There is no numerical limit; replicas can replicate. All follow the same command, action, and duration rules, acting no more than once per round.

Multiattack. The Mephit makes one Rend attack, two at Sorcerer level 6, three at level 12, or four at level 18.

Rend. Melee Spell Attack: your full Sorcerer spell attack modifier to hit, reach 5 ft., one target. Hit: 1d8 + that full modifier Cold damage; 2d8 at Sorcerer level 6, 3d8 at level 11, or 4d8 at level 16 (plus the modifier at every level).

Frost Burn. Immediately after its first Rend hit on its turn, the target makes an Intelligence saving throw against your Sorcerer spell save DC. On a failed save, it takes 1d6 Cold damage (2d6 at Sorcerer level 6, 3d6 at 11, 4d6 at 16) and subtracts 1d4 from its next saving throw after this save and before the end of your next turn. This penalty doesn't stack. On a success, no damage or penalty.