Mockingbird X generic, one blue creature Bird Bard 1/1 Rare Flying You may have Mockingbird enter as a copy of any creature on the battlefield with mana value less than or equal to the amount of mana spent to cast Mockingbird, except it's a Bird in addition to its other types and it has flying
Being able to steal a players commander is often one of the most impactful plays in the format, and being able to do it for a measly two mana makes it clear that this card surely deserves its over-$200 price point on the secondary market
According to WotC, This will give current Standard cards more longevity
it lets you play both black Werewolves, as well as white effects like Rule of Law and Deafening Silence
It can helm a Commander deck, it has to be exiled or dealt with in a way that doesnt kill it to get rid of it, it has card advantage built in via combat, and even has llamas in the art