[Snout] O Bottom, thou art changed! What do I see on thee?
[Bottom] What do you see? You see an ass head of your own, do you?
[Quince] Bless thee, Bottom; bless thee. Thou art translated. (III.i.)

Chaos and fear ensue immediately after Puck casts a spell that exchanges Bottom’s human head for that of a donkey. Although Bottom’s “translation” is the only physical metamorphosis in the play, it echoes the many transformations that take place in Ovid’s Metamorphoses, a Latin poem that Shakespeare drew on heavily in writing A Midsummer Night’s Dream. Despite alluding to classical mythology, however, Bottom’s metamorphosis actually results from fairy magic, and his companions humorously misinterpret the event as a demonic curse—hence Quince’s impulse to issue blessings. This mishmash of references amplifies the humor.

Why are you grown so rude? What change is this,
Sweet love? (III.ii.)

After Hermia wakes from her sleep to find Lysander gone, she tracks him down, only to be met with harsh insults from her betrothed. In these lines she asks Lysander what has turned his “sweet love” so bitter. Lysander’s emotional transformation is, of course, the result of fairy mischief. His transformation is also metaphorically linked to the many other changes in affection that occur in the play, including Demetrius’ shift from Helena to Hermia (and back to Helena) as well as Titania’s shift from Bottom back to Oberon.

But all the story of the night told over,
And all their minds transfigured so together,
More witnesseth than fancy’s images
And grows to something of great constancy,
But, howsoever, strange and admirable. (V.i.)

As against Theseus’ skepticism regarding the lovers’ story of their night in the forest, Hippolyta utters these lines to express her belief in their story. She cites as evidence of the story’s truthfulness the fact that “all their minds [have been] transfigured so together.” Hippolyta’s use of the word “transfigured” is significant, since it indicates not just transformation, but transformation into something better, more elevated. Thus, the lovers’ minds have all undergone a metamorphosis that has brought them to a higher, nobler place. The positive valence of this transformation clearly indicates that “something of great constancy” has transpired.