Kathleen the Cow is one of Sesame Street’s menagerie of Muppet cows, a group that also includes Gladys the Cow. Kathleen's name originates from her starring role in Episode 3586, where Telly Monster and Lexine teach her about what love means.
The puppet has often been used as a background character in street scenes, inserts, and musical numbers such as "Get Along," "Boogie Woogie Piggies," and "If I Were The Letter B." Another starring turn for the cow was as the lead singer on "The Sneeze Song" (voiced here by Marilyn Sokol), backed by a Pig, a Sheep, and Fred the Wonder Horse.
- Occasionally, the Kathleen puppet would be used for cows with different names. In the "The New Here is Your Life" sketch which focuses on Prairie Dawn's Glass of Milk, the Kathleen puppet is named Bossy and performed by Camille Bonora. In the "Law and Order: Special Letters Unit" sketch, the cow is named Murray, played by Eric Jacobson, and is considered the missing letter "M" because it makes a moo sound.
- In A Muppet Family Christmas, the Kathleen puppet is performed by Richard Hunt (using a voice similar to Gladys) during "Deck the Halls."