Leviticus 1:12 (ESV)
12 And he shall cut it into pieces, with its head and its fat, and the priest shall arrange them on the wood that is on the fire on the altar,
Included in the sacrifice were the head and fat portions which the priest was to arrange on the altar.
8 And Aaron’s sons the priests shall arrange the pieces, the head, and the fat, on the wood that is on the fire on the altar;