"Ænema" is a Grammy Award-winning song by rock band Tool, released as the third single from their second album Ænima. Adam Jones made a video for the song using stop-motion animation that appears on Salival. The song reached number twenty-five on the U.S. Mainstream Rock Tracks chart in August 1997.

The song makes extensive use of hemiola, a musical technique in which the emphasis in a triple meter is changed to give the illusion that both a duple and a triple meter occur in the song. For example, during the first verse, the beat appears to be in 12/8 timing, while toward the middle of the song when the lyrics from the first verse are repeated, the beat can be perceived as being in 6/8 timing. The double bass drums are played in a triplet using the floor tom in the middle of the song making them seem twice the speed.

Keenan incorporates into the lyrics part of comedian Bill Hicks' sketch "Arizona Bay" routine (from Hicks' comedy segment album of the same name) by stating the line "learn to swim, see you down in Arizona Bay." Hicks appears in the liner notes/sleeve as a doctor, and a lenticular image below the case tray illustrates a large portion of California disappearing leaving only the Pacific Ocean, as is mentioned in the song. California falling into the sea is a prediction made by Edgar Cayce, also known as "The Sleeping Prophet," about the end of days in which California and New York are to sink into the ocean among a plethora of other devastating weather changes.