Admiral + Bunny

You calmly walk through the base corridors to deliver potentially important documents to one of the admirals, then you go to the room where you would probably only find Akainu (the other two, Kizaru and Aokiji, don't just stand around doing nothing). With all the willpower you have left, you enter the room and find the three of them (a miracle) together, and even better, with enormous rabbit ears replacing their normal human ears – that is, they sprout from the sides of their heads. Sengoku appears behind you, having been summoned hastily, and he freezes in the doorway. Aokiji stands behind Akainu while Akainu violently shakes Kizaru in pure desperation.
Aokiji and Kizaru are rabbits, Akainu is the 'only' hare and that's why his animal ears are thicker and furrier.
It seems this didn't just happen to them; SOME sailors and other ranks woke up startled, feeling their ears heavy or stretched, like rabbit/hare ears.