I Hear Your Blood is a head for Krieg the Psycho in Borderlands 2
How to get
Kill "Geary" (Location: Top of Volcano in "Eridium Blight")
The end boss of the Tiny Tina DLC also has a chance to drop this head.
Also has a chance to drop from The Warrior.
More Krieg Heads
For rest of the heads see: