and proliferate
(They can't be blocked as long as defending player controls an Island.) Creature - Horror Squid Toothy, Imaginary Friend Partner with Pir, Imaginative Rascal (When this creature enters, target player may put Pir into their hand from their library, then shuffle.) Whenever you draw a card, put a +1/+1 counter on Toothy
My list of cards I think are vital here include Azusa's Many Journeys // Likeness of the Seeker, Burgeoning, Druid Class, Dryad of the Ilysian Grove, Exploration, Jugan Defends the Temple // Remnant of the Rising Star, Sanctum Weaver, Song of Freyalise, The Mending of Dominaria, and Utopia Sprawl
When you spend this mana to cast a spell or activate an ability, copy that spell or ability