YOU SAID:
He is my brother in elephant is similar
INTO JAPANESE
彼は象の私の兄弟です似ています
BACK INTO ENGLISH
He's my brother of an elephant
INTO JAPANESE
彼は私の象の兄弟です
BACK INTO ENGLISH
He is my elephant brother
INTO JAPANESE
彼は私の象の兄弟です
BACK INTO ENGLISH
He is my elephant brother
That didn't even make that much sense in English.