Futurama writers.

But yes

that picture is from Futurama

Australia! Could please stop trying to kill people!

I think the earliest instance of "brain worms" I remember was from an episode of Invader Zim in 2001. Zim is offended at the concept of paying to ride a filthy, poorly maintained bus and shouts at the driver "Have you the brain worms?!"

Edit: found the video https://youtu.be/BiqTTozWNhA?si=bxNeTnreb77vdd00

Wait, I'm supposed to be checking my carpet for pythons?

I'm pretty sure Simpsons writers first write and then unleash it in the world, not the other way around.

So the eggs in the egg salad...

Correct! Worm eggs!