Grullo is a strong dun stallion. He is very respectful of Hold On.
Like most grullo duns, Grullo is a grayish silver color with either a black mane and tail, or a type of shade of gray. He has a black line running down from his mane to his rump, or even his tail, because he is a dun.
Grullo is mostly quiet, but not considered shy. He is very strong and a little bit grouchy. He didn't prefer being very social, in other words, he was a bit antisocial.