A frog.
uncle
Grandmother
Your Uncle.
Your mother's mother is your grandmother.
He is your uncle, in most families he would be Uncle (Jack, Fred or what ever his first name is).
brother
You could call them as a brother/sister or as a cousin... If you're asking for yourself then good luck with that family.
In Farsi, you would say "amoo" for mother's brother.
His relationship to you is brother-in-law.
uncle
group of mothers
Your mother's son is your brother or your half brother.
A cousin brother means , the son of the father or mothers , brother or sister.
papu