Broom Hatter makes an appearance in Kirby Star Allies as a helper. His ability, just as before, is Cleaning. He loses his witch hat when befriended, instead getting a white and green kerchief on her head. His gender appears to have been changed from other games, having previously been referred to as a "she". This may indicate that the Ally is a different character from the Broom Hatter seen in other games.
Super Smash Bros.
Broom Hatter is an apprentice witch with the hat to match. She uses her trademark broom to fly through the --- Wait. No, she just sweeps the floor with it. Maybe she's just a bit of a clean freak. Or maybe she hasn't learned to fly yet. After all, she's only an apprentice. Except...in Kirby Air Ride, she DOES fly, so there goes that theory...