Of all the Ninja Turtles, why use the one who most resembles a stoner (laid back attitude, constant appetite) instead of Leonardo, who is the most responsible of the team? "Because he's more popular", of course, but that ignores whyhe was popular.
Perhaps to combat claims that he was a stoner, not that it worked.
Maybe as an in-joke to the people who think Mikey's a stoner? Presumably those people are already old enough to know to say "no" to drugs. The kids who are supposed to be learning from the show probably wouldn't associate those "symptoms" with drug use.
Maybe he's trying to get over his stoner days? This is a kind of recovery. Or the whole thing is his hallucination.
Yeah, the rest of the turtles were off fighting Shredder.
He's actually more of a surfer than a stoner. Back then stoners weren't as omnipresent in popular culture, so it might be a case of Harsher in Hindsight
Any of the other Turtles would arguably be a better choice. Hell, you could probably make a case for Krang.
Leonardo: Responsible, mature, natural leader. Could point out that no one on drugs could handle the intense training he had to endure to become awesome, and that Michael should be a better role model to his younger sibling.
Donatello: Intelligent and scientifically minded. Could explain the biological effects of drugs, and how the brief euphoria is not worth the long term damage Michael is doing to his body.
Raphael: Rebellious bad boy. Could tell Michael that being a cool guy who rejects authority doesn't mean one has to be a lawbreaker, and that forging one's own path includes not bending to peer pressure.
Michelangelo: Thinks THC is a pizza topping.
Despite the above troper's apparent fixation on drug use, Michaelangelo has never in any incarnation of the mythology ever been a drug user. His archetype is "surfer" or "valley dude" and every one of the TMNT are known for their love of pizza. When Raphael is presented as a better role model, credibility begins to get strained.
Has it ever been confirmed that Jim Davis was opposed to Garfield's appearance here, especially since they got the approval of the syndicate and tapped Lorenzo Music to do his voice? I would think that at this late stage of the internet's existence, people wouldn't be so credulous as to cite Wikipedia and iMDB "factoids" as gospel without a proper source.
The syndicate was able to approve of Garfield because they own the Garfield cartoon. However, since the character of Garfield himself was created by, and owned by Jim Davis (remember, Garfield was and still is a daily comic strip), this is how he got upset and threatened to sue if it was ever rerun. I'd sure like to know how the Special got a VHS release though.
The syndicate owned both the Garfield comic and cartoon at the time. Jim Davis bought the rights to Garfield back in 1994.
Rights issues don't seem to be as complicated for VHS (or weren't in the 90's), as there were a bunch of shows and movies with VHS releases that have yet to get DVD releases, despite much fan request.
Mark Evanier, head writer of Garfield & Friends debunked the rumor about Jim Davis suing the producers of this special.