One of the blemishes we mentioned in the previous Mishnah is when the mouth of the Bechor (firstborn animal) looks like a pig. We said there was a machloket (dispute) between one opinion and the Chachamim (rabbis). One opinion said it was a blemish, but the Chachamim said it was not a blemish when the upper jaw sticks out past the lower jaw. Here we'll give the inverse case, where the Chachamim will even agree. There was a case where the lower jaw of the Bechor stuck out past the upper one, the opposite of the case in the previous Mishnah. This question was sent to the rabbis to decide: Is it a blemish or not? The rabbis said it's a blemish, and the Bechor is disqualified. So even the rabbis agreed in this case that it is a blemish.
If a Bechor goat had a doubled ear, so that one of its ears had another, smaller ear growing inside it, the cartilage at the top may have folded over and connected to the head while the ear was growing. Then the animal's head grew another smaller ear inside the main ear. Chachamim say that when the double ear is connected at the top, so that both ears share one piece of cartilage, it is considered a blemish and the Bechor is disqualified. But if it is not made of one piece of cartilage, and each ear has its own cartilage, it is not considered a blemish. Even though generally we say that with an extra limb, like an extra leg, the animal is disqualified or blemished, an extra ear is not really that noticeable.
Rabbi Chanina ben Gamliel omer, this rabbi says: If the tail of a goat looks like that of a pig, which means it was round instead of being wide and flat, or if the tail of the Bechor sheep is very short and does not have at least three bones in it, it's a blemish and the Bechor is disqualified.