Opponent’s first devolve gave me a target dummy, I covered it with magnets knowing the previous/intended interaction being that if there isn’t a minion for an evolve effect then it remains unchanged.
The second devolve turned the target dummy into a snowflipper penguin.
Unable to post links or images, a screenshot does exist but you’ll just have to believe me I guess.
they announced it back then
Cards that “transform a minion into a random one that cost (1) more/less”, like Evolve or Devolve , will now always reroll the minion, even if no minion exists in the target-cost minion pool. The minion will be rerolled at the nearest possible cost. Examples:
When you Devolve a Target Dummy , because there is no negative-cost minion, it will transform into a random 0-cost minion.
When you Evolve a Shirvallah, the Tiger , because there is no 26-cost minion or another 25-cost minion, it will transform into a new Shirvallah the Tiger.