Which animal has the longest penis?

Written by HeyDoctor Medical Team

Everything you always wanted to know, but were too afraid to ask.

Biggest of the big

Unsurprisingly, it’s the biggest animal to ever exist: the blue whale. A blue whale’s penis is estimated to range from 7-10 feet long, although “average” is hard to gauge—shockingly, very few people have been around to measure an erect blue whale penis during intercourse. Also, the whale’s penis has a tough outer layer, which is hypothesized to be the way the whale gets an erection, which makes sense as the amount of blood needed to power an organ of that size might be difficult for an aquatic mammal to spare.

There’s a tastefully-mounted (heh) tip of a blue whale penis at the Icelandic Phallological Museum, and the tip alone is about 5 and a half feet long.

On dry land

But isn’t living in the ocean kind of cheating, being less subject to the laws of gravity than us land-dwellers? I’ll tell you who’s not cheating: elephants. They have the largest penis of any land animal, reaching lengths of up to 39 inches.

Honorable mention goes to the Argentine lake duck, bearer of the largest penis in the bird kingdom (it’s not all cloacae, folks), one specimen of which had a penis measuring over 16 inches.

Over in the world of terrestrial gastropods, somehow the slender banana slug has a penis that is the same size as its entire body. The slugs, whose Latin name, dolichophallus, means “giant penis,” are hermaphroditic, meaning they can take on either male or female sex characteristics during mating. They have to choose a mate that’s around the same size as them, otherwise their penis gets stuck and their mate has to chew it off. But it’s apparently nbd, as they can subsequently still reproduce using their female sex organs. Also, their slime is technically classified as not a solid or a liquid, but a liquid crystal that has simultaneous adhesive and lubricant properties. That’s not penis-related, but nature sure is rad.

Relatively speaking

Anyway guess what? The animal with the longest penis relative to its body size is the humble barnacle. I guess when your mate can’t get to you because you’re both busy adhering to the rock face, you bring your penis to your mate. Genius.

The barnacle’s penis can be up to ten times the length of its body. Not only that, the barnacle can increase the diameter of its penis to decrease the chance of ‘falling out’ during copulation in rough or turbulent waters. Pretend I made some kind of ‘motion in the ocean’ joke! There’s only one tiny downside, which is that sometimes the barnacle’s proportionally mammoth schlong impedes its feeding. What can ya do!

How do people measure up?

But what about the home team? How does Homo sapiens sapiens fare in the dick length department? As it turns out, humans invented the ‘actually, it’s about girth’ argument. Humans have the thickest penises of all primates, both in absolute terms and relative to body size. So we’ve got that going for us.

There you have it. Thanks for reading. Go forth and impress/unnerve people with your stunning knowledge of huge animal penises!

The views expressed in this article intend to highlight alternative studies and induce conversation. They are the views of the author and do not necessarily represent the views of HeyDoctor, and are for informational purposes only, even if and to the extent that this article features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment, and should never be relied upon for specific medical advice.

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