New idea for a creature within the MLP fanon universe that I came up with called Silhoutex(name thought of by a friend)
These creatures start out looking like mannequins brought to life by some kind of magic. They all possess their own special magic, allowing them to swallow any other type of creature, copy and add on desired body parts and/or abilities(magic based or not) to themselves, and then remove the remains of whatever they just ate, in the form of re-birthing slime
Once they are out of the body of a Silhoutex, the creature is reformed as if they were never eaten in the first place.
They still remember the process of being eaten and digested, but it is one of comfort and pleasure rather than fear and pain. Even the digestive fluid is comforting rather than painful