Macro grew up as an orphan in the Fishman District before it became corrupt. He was considered the mean person of his fishmen comrades when and before he was with the Sun Pirates.
Unlike the preachings of his captain, Macro, like Arlong, had no qualms at attacking or even killing humans as part of the crew of Fisher Tiger. Ironically, he seemed attached to the young human, Koala. He yelled at Arlong for his harassment of her and cried as his captain took Koala to her village, asking her to stay and sail with them saying that she’s a good girl even if she’s a human.