They were also huge, like a foot long or maybe even longer.
Rare, but not necessarily unrealistic. I've read about at least one documented case from the US of a guy who made 13 inches erect.
There is also reference on the internet of a guy from South America who claims to be around 18 inches, but his isn't natural. He claims to have started hanging weights from his penis a young age (early puberty) to increase his length.
Surgically increasing penis length is also possible.
As much as a third of the erect length of the penis is actually inside the body. They can give you an apparent length increase by severing the tendons that anchor the penis inside the body.
If you see a guy in a porn film and his penis is hanging down rather than pointing out or up even when erect, he has almost certainly had the surgery described above.