Some cards created by Mysterious Cocoon cost more than 4 mana
Steps to reproduce:
1. Play Mysterious Cocoon.
2. Have the opponent destroy Mysterious Cocoon.
Actual result: Sometimes, non 3-cost creatures are added to the player's hand.
Expected result: Only 3-cost creature cards are pulled from Mysterious Cocoon's finale.
AdminWotC_Alan#83938 (Admin, Wizards of the Coast) shared this idea