The Shocked Pikachu meme, which depicts an off-model, astonished Pikachu from the Pokémon anime, has been around for years. How did it catch on?
KnowYourMeme says the Shocked Pikachu meme started on Tumblr in September 2018. It moved from Facebook and Reddit to Twitter.
Always has text, generally a poster's dialogue describing a climax. Event ends as planned, poster works. Off-model Pikachu shocks (not too much but clearly).
Pikachu appears in Pokémon season 1 episode 10, "Bulbasaur and the Hidden Village." Bulbasaur for Ash this episode. At 3:45, the concert begins. Bulbasaur stopped Ash's insane Oddish fight with Misty.
Butterfree relaxes after Bulbasaur kills Starmie. When Bulbasaur inhales sleep powder, Butterfree sleeps. Gang discusses Pikachu's bottom-right meme. Pikachu's blurry animation started the trend.
The meme spread because Pikachu's "I shouldn't be surprised, but I am" attitude embodies a foreseeable yet disagreeable consequence. Given the episode's horrible setting, Bulbasaur reflecting sleep powder seemed unexpected.
Memes fit Pikachu's small, low-resolution face. Brock may lose legs vectorization. Pikachu memes have lower ears and larger eyes. Pikachu's near-universal familiarity and meme's specificity spread it for four years.
Knowing the Pokémon meme's origins and proper use is advantageous since the Shocked Pikachu meme is unlikely to disappear.