[If] a ewe bore [an offspring resembling] a goat, or [if] a goat bore [an offspring resembling] a ewe, it is exempt from the law of bechor. But if it retains some characteristics, it is subject [to the law of bechor].

[If] a ewe which had not previously given birth bore two males, and their two heads emerged simultaneously —- R’ Yose HaGlili says: Both belong to a Kohen, since it is stated, the males are to HASHEM. The Sages, however, say: It is impossible; rather one [lamb] is his and one goes to a Kohen. R’ Tarfon says: The Kohen selects the better one for himself. R’ Akiva says: The fatter one is at issue between them, while the second [one] is left to pasture until it develops a blemish, and it is subject to the law of gifts [to the Kohen]. R’ Yose exempts [it].  [If] one of them died —- R’ Tarfon says: They divide. R’ Akiva says: The burden of proof lies on the one who seeks to exact [something] from the other. [If] a male and a female [were born first], there is nothing here for a Kohen.