Google search: "multiboob".

Sometimes it's fun to search for some weird thing on Google and see what you get. I'm not really surprised at the number of hits I got for "multiboob", but I am impressed with the variety. We've got a nice cross section of Internet weirdness. Let's see if we can't arrange them on a scale form relatively normal to batshit insane.

First we've got this chick, whose name is Taylor Chanel (I'm sure that's her given name). She's got three tits, seems like this is the real deal. This barely registers my odd-o-meter (a tepid 1.3 (yes, I have a method)) I dunno. Maybe I'm just jaded. Seems like more of a medical curiosity than a turn on. I noticed in all the pictures I could find of her she was positioned such that the tri-boob wasn't directly facing the guy, as if he doesn't really want to look at it right in the eye.
Isn't this the kind of thing that, like, eighth-graders who don't even know what a boob looks like think about? It seems like a young boy all fucked up on hormones might well think that the more tityknockers the better, but once he's grown into a man he'll realizes it's just weird. Who knows, maybe this guy's really into it? He looks like a real specimen of humanity here. I bet he does think like an eighth-grader.
Final note: I bet she has trouble finding shirts that fit well.
Actual final note: what does she do about bras? Is there someplace one might buy bespoke hyperbolomastic lingerie?

1.35. Normally, this one'd be lower. I mean, extra boobs are more interesting than extra nipples, right? It gets points because it's from an incomprehensible Russian website, so I'm not sure if it's really porn or some kind of medical thing; I'm leaning towards the latter. Japan usually takes the limelight, but let there be no mistake, Russian weirdness is a force to be reckoned with. I'm certain some ex-soviet likes to beat-sky his meat-sky to this.*

This one, you'd think it'd be higher but no, it's only a 2.1. Why? Because it looks like a fashion (I'm sorry, Fashion!) photo and Fashion! is supposed to be weird and anyway, I've seen Lady Gaga wearing stranger stuff.

Here we go. Solid 4. Love the title of this: "Lots of tits": just what it says on the tin. I like that sort of honestly in smut.

4.8. This is pretty much the same thing as the last image, but it gets higher points because there's some bondage and a gangbang happening  at the same time. Also and old man is locking her leg. Do... do people do that? You know, a lot of people blame the gays for infecting society but I have see waaaaaaaaaay more fucked up straight porn than gay porn. In fairness, at least some of that is simply a  side effect of people trying to hide The Gay, but I think straights people are into way kinkier shit on average than gays. I mean, you know, adjusting for certain technical considerations. (Anal is higher on the kink meter for straights than it is for gays, I mean).

Alright now this is a solid 5. This just freaks me out. It'd be higher if I wasn't pretty sure this is Fashion! too. Man! Weird. Are the rubber nipples really necessary?

6.82. Yeah, the penis growing out of the base of the other penis is a bit off-putting, but I'm more concerned about the coloration of the nipples and glans penes (Yes, I had to look up the plural. The plural of 'glans' is just 'glans' but 'glans penes' sounds cooler. And this is why I keep a Latin dictionary handy.)

7.3. At first glance, I would've put this lower, but then I noticed the picture's filename included the word 'conjoined'. This is conjoined twin porn. Glad I got to see that. (If they're conjoined twins why do they have different color hairs?)

8.008 (Get it!?). I have no idea what's going on here.

From the same Russian website as the second one up there, this one ranks at 8.3 This is just a little to lovingly rendered to be a medical drawing, you know? And all the little extra boob-lumps... gross.

8.968. This one ranks higher because it's a pretty good Photoshop job. Someone took time with this. Think about that.

11. What in the holy hell is this? I couldn't have come up with this if I went and snorted a few lines (with an acid tab chaser) off of Carmen Miranda's corpse at Carnival in Rio. This is fucking nuts! My favorite part: it's hard to see, but it's got a rainbow-colored forked tongue. This is surely what Fred Phelps sees in his wet-mares.

I also found this, confusingly, with 'multiboob' but I didn't want to include it on with the rest because it's off topic. If you're curious, this is a 6.4. Mainly for the way Meg's distended ribcage has been explicitly drawn.

*In Soviet Russia, meat beats you!