Kenny

Kenny is Heinz Doofenshmirtz's old neighbor form Gimmelschtump.

Kenny was mentioned to be Heinz old neighbor in the episode "Lawn Gnome Beach Party of Terror", he never had a speaking role and was only seen waving to Heinz when he mentioned that he was the only friend he had other than the moon.

He was also mentioned in "Got Game?" when Doofenshmirtz was too lazy to tell his entire backstory.