Why weren’t you at elf practice? refers to a popular series of audiovisual remixes of a scene from the 1964 stop-motion flick, Rudolph the Red-Nosed Reindeer.
Rudolph the Red-Nosed Reindeer premiered in the United States on December 6th, 1964.
At some point in the animated film, the Head Elf is seen barging into the room of Hermey, screaming “Why weren’t you at elf practice?”.
The scene wasn’t turned into a meme until 41 years later, when a YTMND site was launched by bobby22 on November 18th, 2005, depicting Hermey, paired with the audio of the Head Elf screaming.
Another page was launched on YTMND in 2009, featuring the scene along with the titular question, followed by a GIF of two puppets engaging in coitus.
Various parodies of “Why weren’t you art elf practice?” were uploaded to the web in the 2010’s, predominantly to YouTube where minor edits were added to the scene, for comic purpose.
The meme started gaining a lot of traction following a Tumblr post on December 3rd, 2017 by drsimetra, which was followed up by numerous edits and parodies both on Tumblr as well as YouTube and Vine.