No, it is not appropriate or respectful to throw insults, playful or otherwise, at anyone, including your transgender friend, or to make jokes or comments about their gender identity or any other personal aspect of their life. Insulting or making fun of someone based on their gender identity, or any other sensitive topic, can be hurtful and offensive.
It's essential to treat all individuals with respect, kindness, and empathy, regardless of their gender identity or any other characteristic. If you have a good relationship with your friend, focus on supporting and understanding them, and refrain from making jokes or comments that could potentially hurt or offend them.
If you want to have fun and playful interactions with your friend, find activities or topics that are enjoyable for both of you and create a positive and supportive environment for your friendship. Always prioritize sensitivity and respect in your interactions with others.