Dr. SMG3 was a fictional TV show within the SMG4 universe, airing on MKTV from 2018 to 2019. It was hosted by SMG4's nemesis SMG3, and he made the show after stopping Waluigi in The Waluigi Arc. It was later replaced by the fictional company Snitch Productions.
During Fishy Boopkins´s challenge to not watch anime for an hour, he began watching several TV channels, with one of them being an episode of Dr. SMG3 where SMG3 was treating Steve and a random chicken, saying "You are the father!", implying Steve was related to the chicken (though it's possibly a joke due to Steve's obsession with chickens).
An episode of the show pops up in SMG3's segment where for that episode, he had Bowser and Bowser Jr. try to mend their relationship. However, all it did was cause Bowser Jr. to burn with his father with a flamethrower. A producer then went up to SMG3 to tell him that his show was cancelled due to poor ratings.
In its final appearance, SMG3 explains how the show was cancelled from its last appearance and makes a small appearance on a screen. The cancellation of the show, he explains led him to start his own production studio, Snitch Productions.