Your comments remind me of one of my old timers. He came from Sichuan. When he was in the university, he would say "Chui(2) Zi(4)" in Sichuan dialect. "ChuiZi" has two meanings in Sichuan: 1) a hammer in English, 2) cock, dick, or penis in medical terms in English. After some time, we dubbed him Hammer. This guy accepted this nickname. But his English pronunciation has strong Sichuan accent, so Hammer sounded like "Ha-ma" in Mandarin. As time went on, we callled this fellow Ha-ma, which means a toad if we put it in English. Before us old timers, his wife call him "Ha-Ma", too.

In summary, my old timer's nickname evolved as follows:

ChuiZi-->Hammer--Ha-Ma.