Sister Mary Elephant is a comedy skit by Cheech and Chong. The recording appeared on the duo's second album, Big Bambu, released in 1972. It was re-released as a single in 1973 and climbed to No. 24 on the Billboard Hot 100 in early 1974 (becoming the only non-music spoken word recording to ever crack the top 40).

Cover sleeve art for the 45 (single) by Paul Gruwell

The title character is an exceedingly prissy, nun substitute teacher (played by Cheech Marin) teaching in a parochial school ("Our Lady of 115th Street") classroom of exceedingly irreverent, noisy teenage boys (all played by Cheech and Tommy Chong through overdubbing). She attempts to teach the class, but the boys totally ignore her. She then tries to get the students' attention by speaking increasingly loudly, to no avail, and then finally screams, "SHUT UP!" at the top of her lungs, in startling contrast to her usually placid manner; dead silence ensues. She follows this with a once again prissy "Thank you". This becomes a running joke throughout the skit.

Sister Mary Elephant announces that she is the substitute for their regular teacher, Sister Rosetta Stone, who has sent her love and the artwork she is making: fingerpaintings and dustcloths, indicating that she has likely been institutionalized. After introducing herself, the class erupts in laughter upon hearing her name, prompting a repetition of the "SHUT UP!"/"Thank you" routine. Sister Mary Elephant then asks a student to give her his knife. He complies, but not quite the way she had in mind (it is heard flying and sticking in the wall with a twang). She responds with another prissy "Thank you". She continues to try to teach the class, during which they continue talking, necessitating further repetitions of her screaming.

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