Why does my rabbit wag its tail fast when I try to pick it up?

Hello, and thank you for your question. Did you just get Fluffy recently? Most rabbits are not accustomed to being picked up if they haven't been handled from a young age. I suspect she wags her tail in an attempt to squirm away. I would take it very slow, and not attempt to pick her up if she is uncomfortable. Start by gently petting her, offering her treats and speaking to her softly. Eventually, you may be able to put her in your lap. The last step is to get her used to being picked up. Always support her bum with one hand, and support her back by putting it against your chest. Rabbits have very strong legs, and can injure their back or legs if they kick out in a panic. Taking your time to get Fluffy used to you will help get her comfortable with you and avoid any injuries.

I hope this helps! Good luck with Fluffy!