PokeLoot is a new feature in pixelmon 3.0.0. It is based on a previous mod for Pixelmon.
Similarly to the Pokemon games, various items can be found on the ground in the shape of a Pokeball, Ultra Ball, or Master Ball (depending on rarity). Inside the ball is a random type of item. This is a new way to obtain items like Soothe Bell and Power Belt without fighting Boss Pokemon or entering creative mode.
You can craft the Item finder to detect an Item.
PokeLoot will spawn hidden grottos from (Black 2/White 2). Hidden grottos are large bushes with a narrow entrance with a Lit area and an item.