RuneScape rare and Holidays items:

Jagex drop gifts on Christmas, Halloween and Easter. The items respawn in all RuneScape world, including wilderness.

Pumpkin:

The oldest of the rare items. Spawned on Halloween of 2001.

Christmas cracker:

Spawned on Christmas of 2001. Each cracker could be open. There was a party hat inside of them.

Party hat:

Party hats came out of Christmas crackers.

Disk of returning:

Once used for players who were banished to Thordur's black hole. You could buy it for about 10gp when there was an npc-disk seller.

Easter egg:

Spawned on Easter of 2002.
 

Haloween mask:

Halloween masks spawned on Halloween of 2002.

Santa hat:

Santa hats spawned on Christmas of 2002. Santa hats give +3 magic.

Bunny ears:

Spawned on Easter of 2003. "Please remember - these are supposed to be just a bit of fun for Easter. We've noticed on previous occasions players hoarding huge numbers of the gifts we drop, and then reselling them for massively unfair prices. This really isn't in the spirit of the occasion. :-) We don't want this to just become an event whereby a few lucky players suddenly become ludicrously unfairly rich. Therefore new holiday drops are non-tradeable and limited to one per player. But hopefully still a lot of fun."