Wolf Apple

Could call it differently, like "Pet Fruit" or something.
It is inspired by the "wolf apple", a fruit that represents about 50% of the maned wolf's diet.
It is a shrub that grows in savanna biomes. It sometimes produces a "Wolf apple" which can be used to make pets able to respawn. Breaking the bushes won't drop anything. The only way to get more is to feed a 'Maned wolf' a 'wolf apple', and after a while it will find a block of coarse dirt to plant a sapling, so it could be obtained.

Feeding the pets the "wolf apple" will create some particles, showing that the pet can respawn. After respawning (at the player's spawn point), the player needs to feed the pet again.

For when the player have many pets, putting a "Wolf Apple" on hand, the pet that could respawn needs to shows the same particles like when we feed them with the "wolf apple".

When respawning, the pet needs to sit, preventing it from teleporting directly to the player.