Its most likely an unreleased crown shop pet. The clockwork owl was thought to be a hybrid pet, until it was released in the crown shop about a month later. I would say that time will tell, however it never hurts trying to find the pet Good luck!
I'm not 100% certain, but I believe Cendre may be referring to the bunny with a unicorn looking horn (or unibunny) that can be found hopping around in Bestia. There's a blue-ish one with a copper-ish horn that runs the track in Circus Maximus and I believe a purple-ish one with a blue-ish horn is next to the girl that politely waves when you first arrive in Bestia-- I always thought that was a great, subtle little addition by the KI team. Very welcoming for sure!
But he very well could be referring to the Spring pets, since there is also a pink one and they too look like a sabre toothed bunny with antlers or horns. Sorry, I saw the word Bunnycorn and immediately thought of the Bestia one that we all have tried like hopping mad to morph for.