Copycat

Spellcasting. The Copycat is a 9th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 18, +10 to hit with spell attacks). The Copycat has following spells prepared:

at will: Prestidigitation, mage hand
1st level (4 slots): Shield, unseen servant

2nd level (3 slots): Alter self, invisibility

3rd level (3 slots): Fly, haste

4th level (3 slots): Greater invisibility, hallucinatory terrain

5th level (1 slot): Bigby's hand

Copy. The Copycat can touch a creature and make it make a DC 18 constitution saving throw, Failure: The Copycat takes one of the creature's traits and any actions that the creature can use because of the trait, it can also take a spell that the creature has prepared and cast it for free one time and it has the spell prepared. The Copycat can stand up on its hind legs for the next hour or until it decides to go back to being on four legs. Once it stops being on its hind legs it no longer has the trait that it took from the creature.

Multiattack. The copycat can make three claw attacks

Claw. Melee Attack: +9 to hit, reach 5 ft., 1 target. Hit: 20 (2d10 + 9) Slashing damage.

Spell steal. Trigger: The copycat is targeted by or is within the effects of a spell. Response: The copycat has the spell that it was affected by prepared and can cast it once for free and has it prepared for the next hour.