There is nothing wrong with wanting to wear appropriate clothing, including for boys a kilt in Scotland a few generations ago, or dress-like male robes in some cultures. There is a huge problem with rejecting reality, for example a boy feeling an overpowering need to dress in girl clothes because they are not boy clothes. What kind of parent gives in to the magical thinking that dressing like a freak will allow their six y/o to be more comfortable with himself, despite the inevitability of freakishness becoming the center of his social identity? If one of my children had wanted to be a puppy (yep, one did), or anything else inappropriate, I would have gently guided them to more suitable outlets immediately. It’s not hard if you’re willing to accept that an adult is better equipped to make adult decisions than a toddler is. [Note: I can see why so many liberals are unsure whether they are more mature than their children.]
My 3 1/2 year old plays like he is a warewolf or Scooby Doo monster sometimes.