Appearance and story
The Ice Dagger is basically a dagger with the ice appearance. When used, instead of killing the victim, the victim stays alive, but in frozen state. It was one of the gifts the Red Clown gave the queen (the Red Dress Girl), but instead of saying what it does, he responds that she will find it out when she uses it. It was used soon after King confronts her on top of the castle, and was stabbed. His body was stored in one of the rooms in castle.
The dagger was used to freeze Crybaby, after she was trapped by the queen. It was found out that the dagger belongs to the Snow Queen and that it can't damage her too. The dagger doesn't appear afterwards.
- It is unknown can the act of true love (that the Blue Boy used when he kissed Lavender) reverse the Ice Dagger effects. It is because the effects disappeared when Snow Queen died, with her soldiers, snow, ice, and her castle disappearing as well.
- If the act of true love can be a key to unfreezing, then it is similar to how was Elsa in "Frozen" able to reverse the eternal winter she set on Arendelle.