Dickgirls are a hentai staple. It's hard to look at hentai in it's various forms for very long until you come across a woman with a penis. For this reason, liking hentai and liking dickgirls seem almost inseparable. Or so I thought. It's come to my attention that not everyone likes dickgirls. I really can't quite understand why, there are just so many reasons to like them. For some, the reason is that it's the best of both worlds. Not everyone who likes boobs necessarily dislikes cock. But that doesn't cover those that don't necessarily like cock by itself. Why should you, the non-cock-loving reader, like the heavily cocked legions of dickgirls? Well, it should be kept in mind that there are different kinds of dickgirls. Lets run down the list.
The Balls-Out Shemale
Shemales are not common in hentai, but they do exist. This dickgirl was most likely never a woman, but is in fact just a man with breasts. There's no vagina at all. Hentai can manage this much better than real life, but I do understand why not everyone can stomach the balls-out shemale's tendency to copulate with men.
Balls-touching factor: 8 (out of 10)
This is probably the most common variety of dickgirl. The hermaphrodite differs from the shemale in that she's most-likely a natural female, altered scientifically or magically to have a dick. The hermaphrodite is also more picky about her sexual habits. Hermaphrodites usually only associate with women and other hermaphrodites. If a hermaphrodite does end up with a man, she's the one getting penetrated. But she does still have balls.
Balls-touching factor: 5 (out of 10)
The Ball-Less Wonder
The ball-less wonder is similar to the shemale, but with a few key differences. The most obvious, she doesn't have balls. To many dickgirl critics, this is very important. Personally I like to see as many things jiggle as possible, but there is another important difference; the ball-less wonder prefers the company of women. As often as not, her dick is only a temporary effect.
Balls-touching factor: 3 (out of 10)
The Clit Dick
After the hermaphrodite, the clit dick is the most common type of dickgirl. Like the ball-less wonder, the clit dick is a temporary effect, usually symptom of arousal. The clit dick's member is quite literally just a very large penis-shaped clit. For this reason, she can't necessarily be thought of as having male sexual organs. Clit dicks are almost exclusively seen with women. Of course, it still looks like a penis.
Balls-touching factor: 1 (out of 10)
Bridget gets his own section. He's not a girl at all; Bridget was raised as a girl by his parents to stave off bad luck or something. It doesn't really matter, this star of Guilty Gear XX is featured in many, many doujinshi and seems to have crossed a line between dickgirl and yaoi. Even in doujinshi where he's paired with a woman (rare), he's still taking it in the ass. Much as Card Captor Sakura was a character designed to turn masses of anime fans into pedophiles, Bridget seems similarly designed to whet the appetite of fans for the taste of cockflesh.
Balls-touching factor: If it feels like more than two fingers, it's probably a penis (out of 10)
Boy in a Dress
Not exactly a dickgirl, but usually still cute enough to trigger a purely heterosexual response. These types cross some line between dickgirls, yaoi and shota-con. The protagonists of these stories are almost always at the mercy of a female master or masters in some sort of BDSM plotline. Often they are disguised as girls for some ostensibly reasonable justification such as trying to get into an all-girls school. The gender-reversal with Boys in Dresses is more complete than a simple change of clothes. Their mannerisms are far from male, and almost hyper-female. Rarely are they willing sexual participants, and when sex does come up, they're never in the dominating position. Indeed, Boys in Dresses are usually at the mercy of their mother/sister/classmate/teacher. In many ways, they look and act like dickgirls with small breasts. Dickgirls that just happen to be lesbians, keep in mind. You won't find many Boys in Dresses paired with men.
Balls-touching factor: The only thing getting in their ass is made of plastic.
So we understand the types of dickgirls, but what drives many people to like them so much? Mainly, dickgirl fans like scenes where no man is present. The attraction of lesbian porn is nearly universal among heterosexual men. But I think we're all aware of the sometimes overly slow-pace of lesbian porn and the lack of a money-shot is a bit anti-climactic. The use of strap-ons seems to cheapen the scene rather than liven it up. For hentai, there isn't a real reason to draw a strap-on when you can simply draw a woman with a girlcock. This allows a scene to retain the lesbian feel and the lack of a male presence, while gaining real penetration and an often explosive money shot.
Of course there are some that simply like the idea of a girl with a cock, as can be illustrated by the popularity of real-life shemales among porn fans. Some quite like cock, as long as it's attached to a girl. This in itself is not exclusively gay, just make sure the balls don't touch.