ShiroKori, The Moonlit Koi

Rythm of the Stream — Whenever you draw your second card each turn, Shirokori gains a +1/+1 counter. After that, each additional card drawn this turn gives another +1/+1 counter.

Spawn of the Depths — {u} Remove a +1/+1 Counter from ShiroKori: Create a 1/1 blue Fish creature token with islandwalk.