A magical bracelet

It is a very old gold bracelet with glass eyes of different types of creatures, from cat to dragon, plated onto it. It is very scuffed but still gleams intensely when hit by the sun's rays. It is originally only a half an inch with eyes the size of a nail head, and only eight of them, an eagle, a fox, a badger, a lynx, a weasel, a cluster of bead-sized ant eyes, a porcupine, and an axolotl. These eyes become bigger and more is created the more times the item is used. The item has been unable to be damaged by any method used against it as of today.

it is probably around a fifth of a pound but feels like air to the wearer.

Gold, glass, and a very, very powerful mage's blood

That date is lost in time

The magical effect of this bracelet is that the wearer can summon any creature they want to fight for them, or have a weapon based on the creature's abilities given to the wearer. The price is that a) you cannot take the bracelet off and b) the bracelet slowly expands up the arm of the wearer, encasing the wearer in gold and glass eyes, steadily taking the functionality away from the fingers, elbows, shoulder, and eventually the entire body. The good thing is that it only expands when it is used, so you could never have anything come of it except there is a nice looking bracelet permanently stuck to your arm. It grows depending on the size and how dangerous an animal/weapon is. For example, a weapon or summon of an animal like a fox would be a quarter to a half-inch, a wild cat would be an inch to an inch and a half, and something like an ox or bear would be three inches. Summoning a magical creature seems to double the growth. You can back out of actions, since it does take a while to expand across the body, and you need to be touching the eye the entire time to successfully summon a creature, though any growth that happens does not revert. The creatures are not alive and their only purpose is to serve the summoner and disappear after that purpose is served

Eurn used the bracelet a few times, so it is three inches around his forearm. It is said that if you use the bracelet enough, you can summon a hyper being, stronger than the gods and creator of the universe. None have lived long enough to test that theory, and the ones who can are smart enough to not even try.