הפרוטייות - With this variety of mule, it was difficult to tell which of its parents was the horse and which was the donkey; as such, they could not be worked or bred together.  The תפארת ישראל says that these are merely young donkeys, for whom the typical signs that allow us to determine their lineage - a thin voice, short ears and tail would indicate its mother was a horse - have not yet developed sufficiently to make such a determination.

והרמך - The רע"ב says that this species' mother is always a horse, and so one רמך can be bred with another; the רמב"ם indicates that it is a type of horse and may be bred with other horses.

ואדני השדה - This translation is given by the תפארת ישראל, who says that the orangatang was often trained to behave like a human and wear clothing and to sit a table and eat with utensels.  He does bring in the בועז the seemingly dubious interpretation given by others, including the רע"ב, who say that it was a creature tethered to the ground by a cord connected to its navel, was called the ידוע and was the ידוני used by necromancers.  It had hands, feet and the visage of a human, and would kill anything that it could reach; it was hunted from afar with a bow and arrow, which, when it severed its umbilical cord, would cause the creature to emit a bitter cry and instantly die.  The תפארת ישראל is extremely skeptical of the existence of this creature for obvious reasons.

חיה - This classification, along with similar ones given in the next משנה, is relevant according to the רמב"ם, for the purposes of agreements to sell all of one's חיות or בהמות.

וחולדת הסניים - The רע"ב says that this is a rat that lives in bushes; the point of the ת"ק is to classify it as not one of the שרצים whose dead bodies convey טומאה only by touch; according to R' Yose, Beis Shammai were uncertain with regard to the beech marten and so gave it the stingencies of both שרצים, in that they are מטמא by touching a נבלה in an amount as small as a lentil, and of בהמות, in that they are מטמא by carrying a נבלה, albeit in an amount of at least an olive.

ואדם - A man may be harnessed with an animal to pull a plow or do other work.