Starmetal Striker

Weapon (light hammer), rare (requires attunement)

This light hammer was forged using the remains of a comet and is cold to the touch. You gain a +2 bonus to attack and damage rolls made with this magic weapon. Targets hit by the hammer take an extra 1d4 cold damage. The hammer leaves behind a crackling mist when thrown and immediately flies back to your hand after making a ranged attack with it. 

"Comets are said to return every few centuries. Heh. I like this one's return much more."