Peryton

I think Minecraft should have Perytons. If you don't know what Perytons are, I'll tell you. They are mythical creatures that are a half deer half bird hybrid. They look like a bird, but have a deer head. Perytons in Minecraft should have around 30 HP, and should be neutral mobs that do 3 hearts of damage per attack. When enraged, Perytons will act like zombie pigmen and nearby Perytons will attack the same target. Perytons will fly very high up, above the y level of 200. If a player is at build limit height or higher, a Peryton will come and attack the player to defend its skies. You can tame a Peryton with a rabbit foot, and when tamed you will be able to ride it, but when you dismount the Peryton, it will start to attack you, so flight before the elytra won't be that easy or overpowered. Perytons could also have extremely rare Peryton nests near build limit, where Perytons could spawn and rest. You can also breed Perytons, but you can't breed two Perytons together. You can only breed a Peryton with a Horse. The offspring will only have a 10% chance or lower to be a baby Peryton, but has a higher chance of just being another horse.