I can’t believe it took me four years to find out about “Childrens Hospital.” I recently heard series creator Rob Corddry talk about it on “The Daily Show,” tuned in, and developed a bad case of “Childrens Hospital” fever.

The show, which launched season 4 in August (Adult Swim, Thursdays, midnight), is, of course, set in a children’s hospital named for its founder, Arthur Childrens. The chief doctor, Chief, is a hunched woman in a walker. Her voice sounds so familiar. OMG, it’s Megan Mullally! When she isn’t awaiting the Rapture, Chief performs brain surgery, including a successful operation on herself to cure an ailment that made her spontaneously burst into song. Sadly, she was struck by a car while doing a celebratory dance.

This season, “Madonna” (portrayed by a broad-shouldered man in a wig) dropped by, hoping to write a song that transforms doctors from unsung heroes to “sung heroes by singing about them.”

Corddry plays Blake, above, a doctor with clown paint on his face and a butterfly-shaped blood stain on his scrubs. Thank you, “Dr. Blake,” for cooking up a hospital sitcomedydramedy that TV hospital show fans could never have dared dream of.