From the Super Mario Wiki
Queen Hisstocrat is a feminine, fuchsia-colored variant of Hisstocrat who appears as a boss in Super Mario 3D World. She serves as the boss of World Bowser-B: Hisstocrat Returns, and re-appears alongside Hisstocrat as two simultaneous bosses in World Flower-12: Boss Blitz. She fights very similarly to Hisstocrat, where the only difference is that she rains fireballs instead of boulders upon emerging from the ground, which leave temporary fiery puddles the player must avoid. She also spits fireballs as well. As Hisstocrat, she sends up fuchsia-colored snakes, several of them holding plates. A Super Bell can spawn on a plate, giving players opportunity to transform into Cat Mario in order to climb up the snakes to stomp on Queen Hisstocrat.
In the Boss Blitz version of the fight, both Hisstocrats have fireballs raining down, and when one Hisstocrat is hit, the remaining Hisstocrat pauses and cries, giving the player an opportunity to strike that one as well.