"Mack" refuses to use his real name, so just call him Mack and all'll go smoothly. He's Milo's best, and technically only friend, growing up with him and having a part-time job at the Briggs' power plant. He's a surly, cynical snarker who acts as Milo's moral conscience and keeps him from doing anything TOO evil, and it's the only person (Milo's parents included), who has the balls and ability to tell Milo no and actually have to kid listen to him. Mack is also the token heterosexual, so he and Milo have typical Nutty Cuckoo-lander/Realist Jerkass, polar chemistry without any of the sexual tension. He is, effectively, the Kyon to Milo's Haruhi.