The early bird is a 1m tall mob. It has a pair of long, black wings with orange flight feathers. It has long legs with yellow flight feathers. It body is small and grey, with red stripes. It has a scaly, grey-green foot with 2 toes, a hallux, and a sickle claw. Its claws are white. They make squawking, screeching, and growling sounds, without opening their mouth. They can be put on a leash.
They can glide, and fly for 5m in any direction. It can walk through leaves, and on other leaves, at the same time. It spawns in the jungle. It will silently swallow whole any parrots or kittens that walk or fly past it, or land on the leaf block it is in. It will also swoop down to catch parrots, kittens, and fish. They sometimes swoop down and attack mobs, giving them poison 1 for 20 minutes. Once they stop taking damage, they swoop again and attack again. If the attacked one dies, they grab the meat and fly off. If they don't, they will quickly fly away. They are like a neutral mob, but start hostile and become passive, and run, fly, or glide away, on attack.
They can also be made passive by giving them tools. They can then be tamed with fish. When tamed, they can poison player who attack you, but will need some swords or axes to affect zombies and skeletons. They cannot mine. They make sounds when sitting down or standing up in leaves. They will collect meat items on the floor, and will bring them to their owner. They will sit on their owners head, and will noisiling fall off if their owner looks up or down too far. They will not eat the parrots of their owner, unless they have left the early bird for a day, and they are not looking. They will freely eat another player's parrots.
It can walk through leaves, and on other leaves, at the same time.
Huh? Even in Minecraft, a single entity cannot actually be in two places at once. Even really large ones like dinosaurs or ender dragons.
It will silently swallow whole any parrots or kittens that walk or fly past it
No, at least not without a chance to get it back. Instant loss of pets that can teleport to you doesn't usually go over very well, but it might go over if the loss was not only not instant but a deliberate choice (if you can't be bothered to save your pet, you should lose it).