The P.E. teacher's name roughly means "Two-Nine-Rice-field Meatman." Though the meat part can also mean flesh or the physical body. Also, reading 二九 (2-9) is a common pun for niku (meat). The da in nikuda which means rice field is a super common kanji in family name suffixes. His personal name of Nikuo (the machine translation was a bit off) literally contains the kanji for meat 肉 (niku) and man 男 (commonly otoko, but in this case just o).
Fortunately the raw is available for free and I was able to check the kanji used and the furigana (which indicates pronunciation) was there.