I-I'm a bulge-Litvyak I think this is a pun. もっこり means "erection"/bulge, if you will. リトヴャク shares the same first character with もっこり. (thus, kotoRIvyaku, or bulge-Litvyak). I figured "bulge" would make more sense visually as opposed to "erection," but I can't think of a similar pun anyways, sorry.