This was the pilot episode, although it was not aired until the end of the first season.
This episode is in fact the pilot episode of the show. However, due to a shift in animation quality during the show's development after the pilot was finished and shown to ABC executives, the decision was made to air the pilot last. The pilot also featured a different opening sequence which was never shown on television but its storyboard was later released as a bonus on the DVD of the complete series.
A few times in the episode, most noticeably when Sonic meets Muttski, music from Adventures of Sonic the Hedgehog (1993) is used. The composers are not credited in this episode.
Although Sonic's dog Muttski only ever appeared in this episode, he was a regular supporting character in the Sonic the Hedgehog comic book series (published by Archie Comics) based on the show.
The only episode from Season 1 to not have "Sonic" in the title.