Take the left passage

Left was lucky before, and you cross your fingers that it will be again. The water keeps getting deeper, until it's up to your chest, and you finally give up on walking and just swim. It's a lot easier, though it is a bit unnerving, not knowing how far away the passage floor has become. Is it getting shallower, or deeper? Is it over your head yet? If you put your feet down, would you touch, or sink?

Suddenly, something brushes against your thigh and you jump, legs flailing as you kick out reflexively. You almost go under. You tread water, looking all around beneath the dark surface, but all you can see is a large shadow swimming past you. Your heart begins to pound. Is it a shark?

No, it can't be. The sorcerer said the creatures would fuck you, not eat you. The shadow circles you, and you struggle to keep an eye on it. It touches your leg again and you jerk away. It grabs your ankle and drags you under!

You scream, silvery bubbles rising from your mouth and bursting as they reach the surface, and expect a flood of water to **** you, drown you, but...it doesn't. You close your mouth, waiting for the familiar pressure to start in your chest, your body demanding breath, but...it doesn't. You don't need to breathe.

Well, that's convenient. You chalk it up to the sorcerer's magic, and glance down at the creature still gripping your ankle between his teeth. A shimmering blue horse's head stares up at you, large, square teeth holding tight to your leg, but not really hurting you. His mane is aqua and turquoise, glimmering with an iridescent sheen. On either side of his muscular neck are gill slits, like a fish. He has front legs with hooves, but no back legs, just a fish tail covered in shiny blue and gold scales. He's a hippocampus.