Shriekmaw is on its face a solid value card, but theres a lot more going on here
It's not quite a Dockside Extortionist, but it's not as far off as it may initially look
If an effect allows you to search your library for a card with mana value 4 or less, you can't find Cease // Desist
In some fashion, every creature in the deck is a Dragon
For example, just ask any Modern or Historic player about The One Ring or Orcish Bowmasters, both printed with The Lord of the Rings , a non-Standard set
Nope, it immediately (see, I'm going to keep saying "immediately" in this paragraph to emphasize how little you can respond to this action) became Bayek of Siwa, who definitely (although less immediately) smacked them for 6