So my mole is really just a mole that looks like a nipple?
Years ago I worked in an office where there were a number of burned-out army vets who were legends in their own minds. It was really amazing how all of them were the original model for Rambo.
Anyway, one day they got on the subject of all the wild and exotic women they knew. It was getting pretty dreary listening to them continually trying to top one another, and I was able to shut them up by telling them about the time I dated a woman with three nipples.
And yes, an extra nipple can lactate.
Personally, I don’t find that particularly grotesque. It strikes me as way nicer, say, than a lumbar rib. Some years ago I was having trouble turning my head, and for a brief time my doctor thought that possibly I had been born with a supernumerary rib in my neck. Yecch.
My first biology lesson in college came from my first roommate. He decided that since we were roommates it would be a good idea to reveal his anomaly. He pulled off his shirt to reveal a complete set of nipples, at least 4 on each side. As they descended they became less pronounced but the pattern was unquestionable.***** It wasn’t until my sophomore year that I took Embryology and found out it was not that unusual.
Right. One very common anomaly is to have more than two kidneys, which would be very nice if you ever became a donor for a loved one. 
*****Even the lowest on both sides was more than a freckle.
I have one; only on the left side though; smaller (about 7mm dia) than the main pair, lower down and nearer the middle of my chest, but definitely a nipple.
Shouldn’t The Man with the Golden Gun have posted in here by now?
On my upper/inner thigh, within the “milk line”.http://i119.photobucket.com/albums/o147/upstgeu/third_zpsvroxfisp.jpg"]http://http://i119.photobucket.com/albums/o147/upstgeu/third_zpsvroxfisp.jpg
I’m not doctor, but I did talk to one once. I just thought I had a birthmark, right at the spot where my pectoral muscle turns into ribs. It wasn’t big, no big deal. Then, when I was 17 or so (probably my last visit to a pediatric doctor), the doctor told me that it was a bit of nipple tissue that drifted down my chest a bit during my fetal development.
So, apparently that’s what causes them, and most people don’t know they have them because they just think they’re regular birthmarks, if they notice them at all.
(And yes, I know this is a zombie. I’m answering this for posterity.)
Nipplefoot. Yes, it is too a thing.
I love surprising my patients by pointing out their extra nipples to them. As noted above, it happens in about one out of 40 patients, so I get the opportunity about once every week or three, depending on how many routine physicals I’m doing.
Most folks are unaware that’s what they are; they just considered them birthmarks. But perhaps 10% of them already do know they’re sporting a supernumerary papilla.
I tell them it may be a marker a for super power. But I refuse to tell them which power it might be. Instead I encourage them to discover their power for themselves. And to only use it for good.
Sounds like a new supergroup.
You loved Chickenfoot? Get ready for Nipplefoot.
Without any expertise, it seems to me that it would be more common.
After all, we are fairly closEly related genetically to other mammals, many of whom (cows, pigs, dogs, cats, etc.) whose normal anatomy has multiple pairs of nipples. So tit would take less changes/errors during fetal development to result in multiple nipples. But I don’t know of any mammal that normally has more than 2 testicles. Presumably that is a more significant deviation from the norm, and thus less likely to occur.
If she’s Lily Allen, I volunteer.
Nipplefoot is OK, but I just CAN’T STAND Nippleback 
Do supernumerary nipples in women usually develop into breasts?
But if they did that, they probably would not end up under your care.
Two words for you to Google: polymastia and polythelia.
Wow, whadda typo.
Just to be sure, before I look them up, are those two words SFW to Google?
Also Krusty the Clown, ISTR.
Welcome upstgeu to SD. Ordinarily I think reviving a zombie with a “me too” is frowned upon, but luckily the mods were looking the other way. Their loss.
Freudian nip.