The Beast was ordered to series by ABC for 13 episodes and premiered on 6/13/2001. It was pulled after episode five on 7/18/2001
According to TV.com, Naveen appeared as Tamir in all episodes aired, with the possible exception of episode two
Naveen is credited for one episode (episode one) on IMDb
TRIVIA: Sayid was not in the original draft of the pilot episode [of Lost], but the producers knew early on that they wanted an international cast. Executive consultant Jeff Pinkner had worked with Naveen Andrews on a short-lived ABC series called The Beast, and was keen to have him on Lost. The producers were surprised that Andrews was interested in the role. When they cast him, all Andrews was told was that Sayid was from Iraq and had been in the army.
SOURCE: "Before They Were Lost". Lost: The Complete First Season, Buena Vista Home Entertainment. September 6, 2005. Featurette, disc 7
From: Wikipedia: Sayid Jarrah