The avatar you see is just a randomly generated one. You don't see their actual gear/race and they don't see yours. And while I did see a few green pets when I was grinding the Trainer title, most people are taking it seriously/trying to win, so you wont see many of those. Same goes for "silly" pets.
Siamon wrote:I always use my Emerald Proto-Whelp when leveling by the striders. If the strider hit me with Soothe, I just hit Emerald Dream and sleep through Soothe.
What?? This comment is so random and has nothing to do with the topic, oh well.
As for the topic, pvp pet battling was meant to be anomious so what you are looking at is not what the person looks like. So people don't get teased or threatened in game because of what happened in a battle.