Unique Physiology
After Jacob consumed the entire scorpion's heart, he started to feel extremely lethargic, and he knew he needed a massive amount of nutrition right away. So, he began to devour the rest of the scorpion without leaving its bones, biting through them like they were biscuits.
However, he soon found that wasn't enough, so he began to consume the bodies of Andrew and his team, including their hearts. But it only helped him a little as the more he consumed, the more he felt the gulf he needed to fill this time.
In the end, not only did he devour everything, including his reserve, but he even had to consume 40% of his titan tears reserves to feel complete. He had prepared over 100 liters of epic rank titan tears with all the titan iron he could get his hands on, and forty percent of them were gone just like that.