Prompt: So, we've had unicorn!Sherlock. And zombie invasion. But not in the same fic. GO GO GO

...Yeah. I was not drunk when I wrote this. I have no excuse.

Hooves. Horn. Sparkle.

The zombies John expected. The zombies John had prepared for. The zombies John had been hoarding supplies for since he was about eight.

Nothing, however, had prepared him for this.

"A unicorn," he said faintly.

Sherlock nodded, looking distinctly unimpressed with John's inability to cope with such minor fact. Also, distinctly non-equine.

"I need a drink," John decided.

Sherlock looked quite put-out. There was something... iridescent... about his skin. John tried to tell himself it was the adrenaline, but even surrounded by death on all sides in Afghanistan, he'd never hallucinated sparkles before.

"No," John corrected himself, almost wistfully, "If I drink I can't deal with the zombies." He paused. "But if I drink, this conversation will make so much more sense..."

Sherlock's expression was one John privately called his 'most definitely, whatever gave you that ridiculous idea, not a pout' look. John ignored it.

Zombies John was okay with. Zombies everybody expected. Unicorns – unicorns not so much. And so, while John was a little sad to lose the zombies, there really was only one conclusion he could make–

"I must be dreaming," he said, and felt better.

The most-definitely-not-a-pout became ever more pout-like. "You didn't say that when the zombies started rising. You thought it was all perfectly fine." Sherlock said, sounding irritated. "You didn't think it was a dream when the BBC played that footage of Her Majesty picking them off with a rifle either."

"Yeah, but I've always secretly suspected the Queen was capable of kicking arse and taking names in an epic and refined manner. I've never, secretly or otherwise, suspected my flatmate might be a mythological creature associated with... with... virgins ... and hearts... and..." Mythology had never been John's strong point. "...And rainbows."

"Now you're getting me confused with a gay pride parade. Stop it."

"Well, you are sparkling. That's pretty damn gay, and experience backs me up on this – Mister Mistoffelees, Edward Cullen..."

"Honestly, just because a man is capable of an extremely physically demanding dance – Should I mention the Edinburgh Tattoo?"

John had to concede the point. He tried to ignore the half-formed suspicion that Sherlock was hinting he knew of John's participation in the Sword Dance. Which had to come with a disclaimer about how difficult it was or else it just looked... un-Scottish. "Not going to make an excuse for Edward Cullen?"

"There is no excuse for Edward Cullen," Sherlock said darkly.

John nodded. He was never going to forgive Harry for inflicting those books – and then the movies, oh unmerciful God – on him. Speaking of siblings – "Wait. Hang on. Mycroft can't be a... you know, can he?"

"Of course he's a unicorn," Sherlock said, looking insulted. "You do recall the little fact of him being my brother?"

"But Mycroft can't be a unicorn!" John sputtered. "Unicorns are – are – well, all sweetness and light and rainbows–"

"Again with the rainbows–"

"Mycroft kills people! A century ago he'd be the one instigating a war and killing millions of people over the price of tea, and he still might today, I dunno–"

"In my correct shape," Sherlock said stiffly, "I have a horn in the centre of my forehead. It's not for hanging daisy chains."

"..." John said.

"Not to mention, John, have you ever treated a man who was been kicked in the head by horse? No, because they tend to end up in the morgue, where they are of more use to my line of work."

The zombies finally decided they'd been ignored long enough by the moving meals and groaned loudly to reassert their presence.

John gave them a glance, then raised an eyebrow at Sherlock. "Are you more dangerous in this shape or unicorn-shaped?"

"Hooves. Horn. Sparkle," Sherlock said. "Let me deal with them."