Tellah is a character from the Super Nintendo game Final Fantasy II/IV. He's a white mage/black mage, pictured to the left there, and he is most famous for uttering the phrase, "You spoony bard!"
Hella is late-90s West Coast American slang for "very", as in "Hella nice rug you've got there, dude; really pulls the room together." Or: "Do you enjoy obscure bands and expensive coffee?" "Hella."
It also helps that I'm from a small town in Washington State called "Walla Walla," so I'm Hella Tellah from Walla Walla.
Thanks for starting the thread! It's been fun learning the Secret Origins of posters I've been reading for a few years now.