Arbitrarist

You have gained the ability to channel a spirit of pure unrivaled and random chaos when using magic.

• You gain the ability to cast Randomizer as a cantrip. When you do so, instead of choosing any spell, it randomly chooses a cantrip from your list of cantrips.
• Additionally, if a creature or monster of this ability gains this feat, the spell list that is randomly chosen from when cast in this way extends to any innate spellcasting it can do at will.

In both cases, Randomizer as a cantrip does not count as a separate cantrip on your spell list, so you can still have a full list of cantrips, and you can additionally have Randomizer as a level 1 spell as well.