Bottom is a weaver and one of the Athenian craftsmen who are referred to as "the Mechanicals." (These are the working-class guys slated to perform the play Pyramus and Thisbe for Theseus's wedding entertainment.)
During play rehearsal, Bottom's head is transformed (by Puck) into that of an "ass" (donkey), making him the butt of the play's biggest joke. Clueless that he's been transformed, Puck declares that his friends have run away from him in fear because they're trying to "make an ass" out of him (3.1.122). (Yep, that's a case of dramatic irony, all right. We talk more about this in "Symbolism, Imagery, Allegory.") Shakespeare probably got the idea from Apuleius's Golden Ass, a hilarious ancient Roman story about a guy who's turned into a donkey. Bottom's conversion is also key to the play's theme of transformation, a concept Shakespeare borrowed from Ovid's Metamorphoses.
Of course, the joke's not just on Bottom—it's on Titania too because she's been charmed with Oberon's love juice and has a romantic relationship with an "ass." Yes, Shakespeare is making an allusion to bestiality, even though Bottom remains human from the neck down. More importantly, Shakespeare is also making an allusion to another kind of sexual relationship that was considered completely inappropriate: a relationship between a commoner and a royal, which would have been viewed as "monstrous." (This was a big no-no in Shakespeare's day.)
Literary critics have also pointed out that, even though his bond with Titania is primarily sexual in nature, it also resembles a mother-child relationship. Pretty freaky, right? Still, this argument actually makes a lot of sense. Under the spell of the love potion, Titania spends all her time doting on Bottom and lavishing him with her affection. In this way, Bottom becomes a kind of replacement for Titania's foster child, the little "changeling" boy Oberon has taken from her. Yeah, we know. Read our analysis of the "Changeling" for more info about mother-child bonds.
Bottom is the most uproarious of the Mechanicals, ever eager to offer his advice and direction—whether it's wanted or not.
In many of Shakespeare's plays, there's a fellow who seems to be a fool, but actually makes brilliant and insightful points that others can't. King Lear has such a fool, and in As You Like It, Touchstone plays this part, but Midsummer Night's Dream has in Bottom a different kind of fool: a truly foolish one. (OK, fine. He does have one perceptive comment about love and reason, but we think he makes up for it with his overwhelming silliness.)
Bottom unwittingly makes an idiot of himself, expressing confidence about the wrong things and being ever-willing to explain to others as if they were the ones out of the loop. Still, Bottom's idiocy is almost endearingly innocent. It doesn't seem as though Shakespeare is being malicious by creating a working-class character who's also a bona fide twit.
Instead, Bottom is an important character for opening some self-deprecating doors to wonder about the real art and artistry of the theater. Bottom is not so much Shakespeare's comment on whether working-class folks can know and understand theater, but actually, he's Shakespeare's gentle jibe at a lot of the amateur and country acting groups that were on the English theater scene. Some of the most ridiculous lines from Pyramus and Thisbe even come close to lines being performed in simple country versions and children's plays of the day.
Bottom is the only character who mingles freely and openly among the humans and the fairies, at least on stage anyway. (Puck moves in and out of both worlds, too, but his pranks on the human characters are done in secret.) In fact, Bottom cavorts with the fairies like it's no big deal and never really worries about the fact that Titania's love for him is completely inappropriate. At one point, he admits that it doesn't make sense for Titania to love him but then he basically shrugs and says "reason and love keep little company" (3.1.145-146).
Bottom's comfort in the fairy world is similar to the way he happily performs for the court while being oblivious to their mockery. Although he doesn't know it, Bottom, a weaver by trade, manages to "weave" or fuse together the fairy realm and the human worlds of the tradesmen and nobility. (In the same way, Puck weaves these worlds together by traveling back and forth between the two.)
Bottom's particular brand of obliviousness makes him a character who represents what the play is all about: not playing by the rules. Without any self-consciousness, Bottom takes advantage of an opportunity to blur the boundaries of social hierarchy. It's a little joke of Bottom's, and Shakespeare's too, no doubt. The theater is indeed magic, as it's a place where even fools like Bottom can traverse and triumph in all the other spheres of the world.