Ron stood in Moaning Myrtle’s bathroom, nervous, but exhilarated. Myrtle wasn’t there. She’d been crying so hard in her toilet that she hadn’t noticed him creep up and pull the flush. She was probably halfway to the Black Lake by now.

Ron thought about the spell he’d found in Sirius Black’s old diary last summer at Grimmauld Place. The spell he’d been practising in secret for a year. He did feel guilty not giving the diary to Harry, but he had found it, and he wanted to have a go at it first. Harry was always getting attention, and Ron wanted some for himself. And if he became an Animagus! Probably a tiger because of his red hair. How cool would that be?

Taking a deep breath, he finally said the spell out loud: ‘Muto Animali!’ He felt the effects at once. It was rather like Polyjuice Potion, but, thankfully, without the pain. Hair was sprouting everywhere, and he was shrinking. Shrinking? This definitely wasn’t right. He was now much smaller than a tiger. Tentatively, Ron stretched out an arm. To his horror, it was stubby and covered in purple fur! He waddled over to a puddle of water Myrtle had splashed out of her toilet, and peered at his reflection.

Bloody Hell! Ron tried to yell, but it came out as a squeak. When he’d thought about his Animagus form, the last thing he had imagined he’d be was a purple Pygmy Puff! Bloody Fred and George and their joke shop. What the hell was he going to do now? The only thing he could think of was going to Ginny’s dormitory and trying to talk to Arnold. Sirius had been able to communicate with Crookshanks, hadn’t he?

Then a better idea occurred to him. He wouldn’t go to Ginny’s dorm; he’d go to Hermione’s! How many times had he begged Harry to let him sneak in under the Invisibility Cloak? Plus, Pygmy Puffs were cute. He’d be able to get away with anything!

Eventually, he got up to Gryffindor Tower. It took a while: Pygmy Puffs had short legs. It was easy to sneak through the portrait hole and up to the dorm at Parvati’s heels. As the girls got ready for bed, he hopped up onto Hermione’s bedside table and looked cute. Oh, Merlin! Hermione was taking off her robes. And her shirt! So was Lavender. This was so worth an embarrassing Animagus form!

Parvati came out of the bathroom and squealed when she spotted Ron. ‘Oooh! Isn’t he sweeeet! Whose is he?’

‘Ginny’s, isn’t he?’ asked Lavender.

‘No,’ said Hermione, casually unhooking her bra. ‘Arnold’s pink. He is cute, though,’ she cooed, picking him up.

If he hadn’t already been purple, Ron would have turned scarlet as Hermione cuddled him to her chest. Her very naked chest. Ron squeaked and quivered.

‘Ahhh,’ cooed Hermione, ‘he’s scared. It’s OK; you can stay with us. We’ll find out who you belong to tomorrow.’ She put Ron on her pillow, slipped on a nightdress, and lay down beside him, stoking his fur.

Ron purred. He decided he’d worry about the consequences tomorrow. Tonight, he was in paradise.