Altua

Magic Weapons. Altaua's melee weapon attacks count as magical.

Spellcasting. Altaua is a 7-level spellcaster. Its spellcasting ability is Contitution (spell save DC 14, +6 to hit with spell attacks). Altaua has following spells prepared:
Cantrips (at will): Chill Touch, Ray of Frost, True Strike, Frostbite
1st level (4 slots): Ray of Sickness, Ice Knife, Magic Missile

2nd level (3 slots): Misty Step, Snilloc's snowball swarm, Ray of Enfeeblement

3rd level (3 slots): Tidal Wave, Sleet Storm, Blink

4th level (1 slot): Conjure Minor Elementals

Multi attack. Altaua makes 3 claw attacks

Claws. Melee Weapon Attack: +7 to hit, reach 5 ft., Hit: # (1d6 + 4) slashing damage. 

Freezing Strikes. (Recharge 4-6) Altaua uses multi attack. Each attack that hits deals an extra 3 (1d6) cold damage.  A target that is hit by one or more of these attacks has there speed reduced by 10 ft. until the end of Altaua's next turn.