Larsen is a band, not a "dude". It's a very good band. (r) is pretty good too. Likewsie Blind Cave Salamander, another of his things. None of them are much like Mouthus though.
They have a myspace:
http://www.myspace.com/larsentoit
See also:
http://www.myspace.com/fabriziomodonesepalumbo (for he is (r))
http://www.myspace.com/proteidae
http://www.deathtripper.com/intropic.htm
http://www.larsen.to.it/