A koiy

has ways in which

it is equivalent to a chaya

and has ways

in which it is equivalent to a beheima

and it has ways

it which it is equivalent to a chaya and a beheima

and it has ways in which it is not equivalent

not to a chaya and not to a beheima

פרק ב משנה ט

How it it [a koiy] equivalent to a chaya?

Its blood requires covering [after slaughter]

like the blood of a chaya

and it is not slaughtered

on yom tov;

and if it is slaughtered on yom tov

one does not cover its blood

and its chelev causes tumah

with tumas n'veila as by a chaya

and its tumah is of an uncertain nature;

and we do not redeem [with] it

the first born of a donkey.