Dreamtide Whale (59) [Modern Horizons 3]

Vanishing 2 (This creature enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.) Whenever a player casts their second spell each turn, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)