Korst Gogg Thek Lutiven-Day Slitheen is the 12-year-old son of Kist Magg Thek Lutiven-Day Slitheen, the nephew of Glune Fex Fize Sharlaveer-Slam Slitheen, a member of the Slitheen a criminal family from Raxacoricofallapatorius, the tertiary antagonist in The Sarah Jane Adventures episode Revenge of the Slitheen and the main later true secondary antagonist (the real main antagonist being Mr. Smith) of The Lost Boy. As Carl, he is played by Anton Thomas McCormick whilst as Nathan, he is played by Ryan Watson. Both actors voice his Slitheen form which is played by Jimmy Vee.