Crab and Penguin added as experimental features in minor 1.21 versions.

Many people were upset with the mob vote and that I feel its unfair to postpone/scrap big game changing features (in this case: Further block placement and Boosted boat speed) and that it can be challenging to implement all three. Heres a better idea, what about after the release of 1.21 in minor versions like 1.21.1+ there could be an experimental option like the bundle to implement a (basic in game illustration) crab and penguin mob in the game and like I said, they don't have to be perfect (like every feature that gets added in the main update) theres a reason why they are experimental. I believe implementing these mobs would make the supporters of these mobs happier as a way to see them and would get the developers a better idea on how and when to implement these mobs properly. Even better there would be feedback as players would played with them and as developers they can decide what to do with the mobs.