In Standard, it can be cast on Turn 2 after casting either Gilded Goose or Arboreal Grazer, and it plays particularly well with either one, in that Oko and Gilded Goose each make Food for the other one, so you can keep making mana or keep making Elks as needed, and with Arboreal Grazer, you can immediately turn the Grazer into an Elk and attack for three on Turn 2
Decks With This Card Recent public and tournament decks using Pot of Dichotomy
7 Chandra, Gremlin Wrangler Like Dungeon Master, Chandra, Gremlin Wrangler is a Planeswalker card that was printed as part of Heroes of the Realm
Gremlins you begin to control later in the turn won't gain menace, lifelink, or haste
Though it makes me think people won't let you untap with her on the board, since you could easily drop a Triumph of the Hordes or a big green pumper or whatever