In the Prisoner Mines, the Beasts Pirates receive reports that an intruder has broken through all three gates, and all of them are astonished that it is none other than Big Mom.
Luffy is stunned as well, but Big Mom pays them no mind as she smells o-shiruko and calls Tama to come eat it with her. Chopper is shocked at the seeming presence of shiruko, and Kiku tells Tama and Momonosuke to stay behind while she and Chopper cautiously infiltrate the prison.
Inside, Queen is angered to hear Big Mom mention o-shiruko, wondering if she came to take his unknowingly nonexistent supply from him. Despite Babanuki’s warning, Queen transforms into a brachiosaurus with the Ryu Ryu no Mi, Model: Brachiosaurus and stands against Big Mom.
The major strength of this fruit is that it allows the user to turn into a brachiosaurus, granting him an immense boost to size and bulk. Brachiosaurus is a genus of sauropod dinosaur that lived in North America during the Late Jurassic, about 154–153 million years ago.
As an Ancient Zoan, Ryu Ryu no Mi, Model: Brachiosaurus is implied to be stronger than a regular Zoan.
All of this is useless anyway, since Big Mom is not a normal human! This causes Big Mom to grow impatient with Queen, so she leaps up and slams his head into the ground with monstrous force.
Remember, no one can mess with a Yonko!