Not very many actors have the talent (and luck) to secure a lead role on a television show. Even fewer succeed in inhabiting one of those roles so completely that they make the character a permanent cultural fixture. Peter Davison, a true master of reinvention, has managed to do it time and again during his long and illustrious career. Davison stole the show in 1978 as the roguish Tristan Farnon on "All Creatures Great and Small," an adaptation of James Herriot's books about a veterinarian. The series went on for three seasons (though it returned in 1988 for four more), but when it was all over, Davison had much further to go as an actor--all the way across the universe, it turned out, as he was hired to play the fifth incarnation of "Doctor Who." Leaving the tranquil Yorkshire countryside of "All Creatures Great and Small" to jet across time and space in his TARDIS craft (which naturally resembles a 1950s-era London police box), Davison demonstrated how completely he could transform himself for his television audience. After only three seasons of "Doctor Who," he moved on, worried he might be typecast. While many actors do succumb to that pitfall, the rest of Davison's diverse career has proven he had little to fear. From shining a tongue-in-cheek light on suburbia in "At Home with the Braithwaites" to solving crimes as Dangerous Davies on "The Last Detective," Peter Davison has repeatedly risen to each new dramatic challenge and pleasantly surprised his fans.