Marsha is a major character in the Quest for the Extra Ordinary Aliens performance. Her name is a play on the word "Martian".
Marsha closely resembles Mommy Martian, with a dark, purplish-gray suit and green skin. Rather than eyestalks, Marsha's costume includes antennae.
Marsha has not appeared in any episodes of The Backyardigans, but is shown in Quest for the Extra Ordinary Aliens.