Bob pulled the monster's corpse out of his inventory. Then, he began searching for its main organ. He searched, but he couldn't find anything. With Tunny, he found it fairly quickly, but this time it was taking longer. Eventually, Bob realized it was a short black cord that looked like a piece of intestine, with a large white eye at the end of it.
Bob placed it in his mouth. He needed his own blood, so he had to punch himself hard enough in the stomach to get blood into his mouth.
[-200 HP]
Then, Bob simply waited while the monster's main organ floated in his blood-filled mouth.
After a moment, the organ began to tremble. That was the right moment—Bob swallowed it.
Then, he put the monster's corpse back into his inventory, extinguished the candle, and went to sleep.
--
Two hours later, Bob woke up. His entire body was weak and moved sluggishly. If Bob could feel pain, it would have been unbearable—but he didn't.