The wrong spell

Today it is Hexana's turn to show, in front of the class, what she has learned.
Her teacher, witch Armalda, said Hexana need to change the mouse in a bunny.
"Are you really sure you want a bunny and not a frog?" ask Hexana. She can't remember the spell for a bunny and knows only the one for a frog.
"Yes! I am really very sure that I want a bunny and not a frog!"
"Okay! Hapax ... modipax ... rodifaxes rubanix!"
"NO! NOT rodifaxes! Rodifixes! And not ..." PUFF! It is too late!
Hexana create a dragon instead of changing the mouse in a bunny.