Wiksteria Lane

An uncredited extra is a performer who is shown in episodes of Desperate Housewives as either a background player or a stand-in for the main stars.

Uncredited extras are, therefore, "actors" who will be seen in every single episode but won't have any speaking parts and will not be credited along with the main, supporting and guest castmembers. Such extras are usually featured in crowd shots, in walk-on parts, and sometimes they step in for the main actors when a particular episode doesn't require the actual star to play the role.

The following characters have been portrayed, at some point, by uncredited extras:

Character Episode Explanation
Karl Mayer "Pilot" Karl is seen very briefly in this episode, during a short flashback sequence that doesn't show the character's head; an extra was hired for the part, before Richard Burgi had been cast in the role.
Alejandro Perez "Suspicious Minds" Alejandro is shown briefly in a flashback in this episode, several seasons before Tony Plana was cast in the role.
Rex Van de Kamp "Every Day a Little Death" Only Rex's hand was seen in this episode, opening a curtain, so there was no need for actor Steven Culp to show up.
Caleb Applewhite "Next" - "You Could Drive a Person Crazy" Only Caleb's hands are seen in these two episodes. Page Kennedy would make his first full credited appearance in the following episode.
Bree Hodge "My Husband, the Pig" Stand-in Carolyn Howard (uncredited) took over the role of Bree in this short appearance by the character because Marcia Cross went on a maternity leave.
Gloria Hodge "In Buddy's Eyes" Gloria is seen briefly in a flashback, and the character's head is not shown; there was no need to bring Dixie Carter back for such a small cameo.
Wayne Davis "In Buddy's Eyes" Only Wayne's hand is seen, drawing a circle around a newspaper image, so Gary Cole was not present.
Eddie Orlofsky "Nice is Different Than Good" The character is presented as an unidentifiable character who strangles Julie Mayer; Josh Zuckerman would first be seen (also uncredited) in the following episode.
Tom Scavo "Watch While I Revise the World" Tom is seen from the back in a minor flashback in this episode, played by an extra. Coincidentally, this episode broke the streak for Doug Savant's appearances (the longest for anyone who isn't featured in every episode), and yet Tom is still shown.
Porter and Preston Scavo "Putting It Together" The kids are seen, younger, in flashback form, from the back.