Blood of Innocents

Blood of Innocents is used to summon Kirtonos the Herald in Scholomance. If you're particularly evil, you might want to hold on to it.

Source
This item was a reward from the quest Krastinov's Bag of Horrors which starts with Eva Sarkhoff in the Western Plaguelands. To complete the quest, you must slay Kirtonos the Herald and return to Eva Sarkhoff.

Once you had completed the follow-up quest Kirtonos the Herald the formerly lvl 61 elite succubus Blood Steward of Kirtonos in The Reliquary in Scholomance would always drop the Blood of Innocents. Doctor Theolen Krastinov and Jandice Barov also often drops the Blood of Innocents, as it was not removed from their loot drops.

Eva now only gives the quest Kirtonos the Herald and as such, provides the Blood instead. Of course, the Blood Steward of Kirtonos can still be killed for money and random drops.