Board Thread:General Discussion/@comment-27033632-20150930231034/@comment-24810590-20151021022146

I'm just going to point out that they put clothing on Crash Bandicoot, Mario, Mickey Mouse and Spongebob Squarepants, although Sonic far from being the only one who doesn't wear pants. They didn't put pants on Garfield, Felix the cat, Bugs Bunny and most Looney Tunes characters,  Scooby-Doo,  Tom and Jerry, Elmo, Cookie Monster, plus heaps more.

In the world of cartoon, it is completely normal that Sonic doesn't wear pants or have private parts.