Whinny. (A higher pitched neigh)
The most common noise a pony makes is a "neigh" or a "whinny" sound.
"Maaaa." ^ that is the sound a goat makes
it is referred to as a chattering sound.
A sheeps sound is known as a bleat
purrs
bleats
Yes, "pony" is considered a short o sounding word. The "o" in "pony" is pronounced with a long vowel sound, as in "oh." However, it can be confusing because the "o" produces a different sound than a typical short vowel sound. In phonetics, "pony" has a long "o" sound, not a short "o."
The word you want is reverb.
elephant
Neigh.
a grunting noise
a baa I think