Foxxinnia: jclaggett: I read somewhere that he was only supposed to be in one or two episodes, but he knew how to work the espresso machine, so they kept him around.

This information comes from the WB Studios tour so trust it as far as you can throw it, but when they started shooting the Central Perk scenes the set had a functional espresso machine and they asked the extras if any of them knew how to work the damn thing. He apparently had, at best, a vague idea of how to work it, but volunteered anyway as no one else did.

amb: Unsung_Hero: thesharkman: I probably watched a handful of episodes and don't know who this is, how many episodes was he in? It's weird between this and Seinfeld I spent my Thursdays doing anything but watching TV.

He put in a LOT of time in the background at the coffee shop.  I wouldn't be surprised to find he was in every Central Perk scene, but I honestly can't remember noticing him when he didn't have lines about or reactions to Rachel.

I think he was in around half the episodes. I remember seeing the number when the reunion happened, but forgot it other than remembering, wow he was in more than I thought.

RIP Gunther, you were the only friend that didn't sleep with Janice.