Kitty Pryde first appeared in Uncanny X-Men #129 in 1980 using the mutant name Sprite. Kitty's first onscreen appearance was as Sprite in the 1983 episode of Spider-Man and His Amazing Friends titled, "The X-Men Adventure."
In her next appearance, Kitty took top billing in the 1989 pilot (to a series that never was) Pryde of the X-Men. By now, Kitty was known as Shadowcat and was featured with her trademark pet dragon Lockheed.
Now, this is when things get interesting. Most people are aware of Kitty Pryde's live-action appearance in 2006's X-Men: The Last Stand in but Shadowcat was one of just a select few mutants featured in all three X-films, albeit she was played by different actresses. In 2000, she was addressed as "Kitty" and shown phasing through a door just after Wolverine met Professor X.
In 2003's X2: X-Men United, she was briefly shown escaping the X-Mansion raid by falling through her bed.
But it was in the 3rd X-Men film that she got any real presence, taking on and outsmarting Juggernaut.
Of course, peppy Kitty was also an integral character in the 2000 series X-Men Evolution.
Shadowcat is also one of the more prominent X-Men in the current Wolverine and the X-Men series where she continues to solidify her position as a fan favorite member of the team.