Tis the completed version of http://nazrigar.tumblr.com/image/60768151507
Here, in the Mobzilla universe, Slattern is amongst the biggest and most capable fighters in the city (he was 596 ft. in the film, almost TWICE THE HEIGHT OF HEISEI ERA GOJIRA), and runs a large gym with its own boxing ring. The gym however is a front for illegal underground fighting circuit just under it.
Slattern and older Half-brother Knifehead practically live in the gym. Accompanying them in work includes Leatherback and Otachi. Leatherback is the ever reliable lacky of Slattern, but unlike most lackeys, he puts of a great fight. Otachi's a single mother, always bringing her son, unable to afford a baby sitter.
Slattern's and Knifehead's relationship was never too good. Despite being older, he always had a sense of being under his brother's shadow. Slattern was bigger, stronger and meaner all around. The situation only worsened with arrival of Cherno Alpha and his gym. One of Cherno's students, one Gipsy Danger, challenged and actually defeated the welterweight. Slattern was furious at both her and Knifehead. His loss made Slattern and his gym look bad, to be beaten by some mecha new comer was the worst disgrace any kaiju could face.
Someday... Knifehead always thought to himself, he may get his rematch with "The Girl who Ruined Everything".