Krampus Staff. The three elves wield a blackened evil staff. The staff has the following spells that can be cast three a day innately from it with a DC 14:

Dancing Lights
Snilloc’s Snowball Swarm
Frost Fingers

Multiattack. The Three Elves in Santa's Coat makes three claw attacks or one claw attack and cast one spell from the Krampus Staff.

Claw. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 16 (2d6 + 6) slashing damage.

Assemble. If the Three Elves in Santa's Coat takes more than 15 hit points of damage in a turn they must make a DC 12 dex save or fall apart. The can then use one action on their next turn to reassemble.

If they are kept apart, each elf has 46 hp and a ac of 14, they keep their claw attack but only one can wield the Krampus Staff.

Can't Fool Me. While in Santa's Coat the three elves have disadvantage on fooling people to make them think they are Santa.