Merlin's gauntlet

The gauntlet is a magical item that originated from Camelot, and ends up in the possession of Rumplestiltskin. It is used to lead to one's greatest weakness, and is briefly stolen by the Queens of Darkness to be used to defeat their greatest enemies.

Before the Curse
During his visit to Camelot, the Dark One, Rumplestiltskin, picks up a magical gauntlet, an item that can be used to lead to one's greatest weaknesses. When returning home to the Dark Castle and discovering his maid, Belle, snooping around, he poofs up the gauntlet for her to clean. Later on though, the maid is kidnapped, and her captors send Rumple a message via magic sand-dollar that states Rumple must bring the gauntlet to Demon's Bluff in exchange for Belle, or she will be killed. Rumple begrudgingly does as told, and is met with the Queens of Darkness - Maleficent, Ursula, and Cruella de Vil - who have the maid in their possession. The Dark One tries using the force to choke Maleficent, but Ursula suffocates Belle in return, and thus, realizing this is getting him no where, he lets Maleficent go and tosses over the gauntlet. They free Belle, and Rumple takes her back to his castle, and for the first time ever, Belle starts to see the man behind the beast. Later on though, Rumple goes back to Demon's Bluff and retrieves his gauntlet. The Queens of Darkness warn him that the villains never win, and that he should join them instead. However, the Dark One does not listen, as he believes he can get whatever he wants so long as he takes it.