Gus was around from the early 80's to the early 90's. The last time I saw him on there was 1993, right before The Around the Corner garbage started and they introduced all those new charachters and took a lot of the focus off the older ones. I remember an episode from 1991 when Big Bird and Snuffy got in a big argument because of Gus, similar to how Elmo is with Zoe's pet Rocco now. But Snuffy felt the same exact way in this episode about Big Bird's teddy bear Radar, and they were so mad at each other that said they weren't gonna be best friends anymore. I think Oscar was the one who originally got the fight started. He wasn't seen in the same take with Big Bird, but somehow it was some prank he pulled that got the fight started. I think he had something delivered to Big Bird's nest that Big Bird wasn't expecting, not sure how that would start a fight between him and Snuffy but somehow it did. Anyways I think this was the only episode when Big Bird and Snuffy had a fight that intense. This same type of storyline has been seen with best friends on a lot of TV shows over the years.