Mobs can "absorb" items

Certain mobs can pick up items without using them and do not drop them even after death. Examples are:
Foxes can pick up most items near them, but the items simply disappear afterwards.
Certain mobs (including Zombified Piglins and Zombies) absorb specifically Netherite armor dropped as items on the ground, but are still able to equip them through dispensers.
Witches are able to absorb mob heads/skulls if dispensed, but do not drop them after death.

Video: https://youtu.be/xJjELLSjxco