No, this is the official name of Professor Wizgiz’s metamorphosis class.
From magic invocation to self-defense to convergence, the Winx’s magic training guide all their battles and adventures. But the one class whose lessons have seemed to fade into the background is Metamorphosis. Well, not completely. Wizgiz taught his students the importance of honesty and good character, and apparently he was the one who told them about the Tree of Life, which helped the Winx find Roxy. However, they’ve never used what is supposed to be the core teaching of the class: transformation.
It may have come in handy a few times. Imagine if the Winx had used it to hide in Cloud Tower all the times it was taken over, or to sneak into Morgana’s castle to save her from Nebula. Or consider how Duman used his powers: scaring away Artù (cruel but conveinent), making quick escapes, secretly gathering information.
So why has this part of the Winx’s education been ignored? Maybe Rainbow thinks girls won’t want to see their favorite heroines turning into monsters. Why not? Stella got transformed into a frog (or an ogre—it was hard to tell).