Chullin 117 - Which is Stricter, Fat or Blood?
Fat and blood are prohibited in the same Torah phrase, " Any internal fat that is normally sacrificed and any blood you shall not eat ." Both carry an excision penalty if done intentionally and a sin-offering if done by mistake. However, each one has stringencies not found in another.
If one benefits from the internal fat of an animal that is a sacrifice, he has committed a misappropriation of the Temple property. If he eats it after it was offerred by the priest with the intention to eat it after the alloted time, or after it was left actually over, or after he became ritually impure - he is liable, which is not the case with blood. That is because blood serves for atonement, and only for atonement, but not for additional transgressions. One does not commit misappropriation with blood, because it is given "to you."
On the other hand, the prohibition of eating blood applies to domestic animals, wild animals, and to fowl, whether kosher or non-kosher, but the prohibition of eating the inner fat applies only to kosher domesticated animals.
Art: Pieter Aertsen - Vendor Of Fowl