Don't they have a couple? And they're more nerve clusters than proper brains, iirc
Discussion
I'm not aware of there being more than one. That might depend on the specific species of worm.
Earthworm. Just googled. Seems you're right. But "brain" is apparently a bit of a stretch for what they're working with. Then there are nerve clusters here and there, so maybe I was thinking of those. I didn't retain much of anything from biology, not my forte