Gilded Hydra/zh

 is a gun that fires large bursts of piercing, bouncing bullets. Its magazine size is increased by 1 for each half heart the player is missing, and healing any missing health decreases magazine size.

Trivia

 * The decreasing health adding to the clip size (as well as the 2:1 reference) is an allusion to the Lernean Hydra of Greek mythology, a beast that would sprout two heads in the place of one that was severed.