My daughter wore this for her carnival parade and the tail held up through two hours of running around. The fin doesn't drag on the ground either, which was my worry since she's on the smaller end of the 5-7 range.
Avery A.★★★★★
The tail is shiny and the whole thing fits my six-year-old perfectly without being too tight, which is usually a problem with costumes. She refused to take it off after her dress-up party, so I'd call that a win.
Christopher G.★★★★☆
Bought this for my daughter's carnival party and the tail fin held up way better than I expected with all that running around. Only thing is the top runs a bit loose on her, so I'd size down if your kid is between sizes.