Sometimes you gotta give the people what they want, and sometimes, they want tentacles.
Till Human Voices Wake Us by saltandbyrne
Summary: In a world of hippogriffs, hydras and flying pygmy elephants, intrepid explorer Dean Winchester was sure he had seen it all. When a monster destroys the only home he's ever known, Dean finds himself falling for his strange rescuer and struggling to face his past.
Wet and Wild by fairychangeling
Summary: At first, it seems as if the hex bag hasn't worked.Dean doesn't feel any ill effects. He doesn't spontaneously combust or break out in boils, so they chalk it up to the witch being off her game. They're wrong however. It takes a little time to work, but the spell is stranger than anything the Winchesters have previously encounter. Suddenly, Dean is sporting tentacles, and things only get weirder from there.
Could You Be an Angel? by FagurFiskur
Summary: In which Castiel is an alien who abducts Dean, and probing may or may not be on the agenda.
The Siren and the Sea Monster by Ltleflrt
Summary: When Cain moves to Washington State, Dean decides to follow him so that he can keep his job as Cain's apprentice. The small town near the sea is Cain's home town, and he has a small beach house that he rents to Dean for dirt cheap, with only a warning to beware of strange neighbors.
Friends with Benefits with Tentacles by andimeantittosting
Summary: Dean's never been embarrassed about his porn collection before, but that was before he found Cas holding his prized copy of Sweet Princess Asuka and the Tentacles of Pleasure. Dean finds himself sweating bullets—because this is Cas, sweet, nerdy Cas. Cas, his friend. Cas, his roommate. Cas, his—only slightly out-of-control—crush. Cas, with his big, blue eyes and muscular arms and perpetual sex hair. Cas, with his tentacles. The last thing he expects is for Cas to suggest they experiment together.
Deep Blue Ocean by suckerfordeansfreckles
Summary: Dean’s been in contact with supernatural creatures and people for all his life, as far as he can remember. He’s been working as a social worker for years now, specifying on cases that involve supernatural families.
But he’s never really… been with a supernatural creature. He’s never been with anyone, ever, for more than a night, really — not the relationship type, that‘s what he used to excuse it on.
But then he met Cas, on a case he worked with his brother, one in a cecaelia community in California. He met Cas, a cecaelia himself, and was kind of lost right away, because Cas was friendly, helpful, articulate and kind of brilliant. He’s also… gorgeous. When Dean first saw him, he kind of lost all breath and brainpower. They’ve been together for a few months now, but in all this time, they haven’t been intimate, haven’t really dared to go beyond their heavy make-out sessions.It’s especially hard again for Dean today, to not just devour Cas. To not just beg him for more.
The Winchester Circus by Novachester
Summary: A grand spectacle has swept through the land, capturing the hearts and imaginations of all who witness it; The Winchester Circus, a family show that boasts not only talent, but true magic. Their roster spans dozens of species, but perhaps their most noteworthy act is that of a fabled sea monster, a wicked kraken-like beast that does battle with the brave Dean Winchester every show.
What the audience doesn't need to know is that the beast’s name is Castiel, and that he's anything but wicked.