Frost giant jarl corpse message
...there isn't one
As far as I can remember, every edible item has some description when eaten, e.g., "You are done eating the iron ration. Tasted good." Apparently this got missed for frost giant jarl corpses -- the message is only "You are done eating the frost giant jarl corpse" with nothing after it. It may be relevant that the character did not get the strength bonus which sometimes results from the corpse.