The lights were off in the house, and it didn't seem like anyone was home. Harry checked the letter that he had gotten again.

Harry,

Can you meet me at my house? I have a new pet I think you'll like.

From,

Luna.

He wasn't sure why Luna wanted him to meet her new pet, but it gave him an excuse to come visit, so he didn't see why not.

Harry walked up to the door and knocked on it. A muffled shout of "Wait!" greeted him as a light flickered on, which shone out of the window next to the door.

The door opened. "Hey Harry," Luna greeted him, blonde hair all messed up like she'd been struggling with something.

"Hi, Luna," Harry greeted her back. "You wanted me to meet your new pet?" he asked.

"Yes." Luna stepped back from the door to let Harry into the house. "I do think you'll like him, he's very nice."

"Nice?" Luna's definition of nice was very different to a lot of other people's. Harry had a bad feeling about this.

"Yes. Well, he is nice to me, so I think he'll be nice to you." Luna lead him through to the living room, before gesturing to her pet. "Well, here he is. Meet Sid."

"Mama..."

The first thing Harry recognised was the familar hiss in the creature's voice from his second year. Instinct screamed at him to run out or pull his wand out as his body tensed upon realisation of what Sid was. Fighting the urge to run away, Harry turned to look at Luna.

"Luna... That's an acromantula, isn't it?" he asked.

"Yes, it is. Sid's a baby one too. I like him, and he likes me," Luna explained.

"...You do know how big those grow, right?"

"Yes, I do. The person I got it from gave me a potion to help keep him small and a recipe to make more. If we can't make more, me and my dad know Reducio, too." she explained as Harry knelt down next to what looked like a glorified hamster cage containing the acromantula. Sid, rather unfortunately, didn't take kindly to the new person looking at him and hissed and leapt at the wall of the cage, causing Harry to flinch back and fall on his backside.

"Sid, that was mean," Luna scolded the spider.

"Sorry, mama," Sid said apologetically.

"Now say sorry to Harry."

"Sorry..."

"It's fine," Harry said as he got up. "But Luna..."

"Yes?"

"Don't tell Ron you have one. He hates spiders."

"Oh?" she asked. "Why?"

"I don't know, just... he does," he explained.

"Oh. I won't then." Luna turned her attention to cooing at Sid, who gently tapped the wall of the cage he was in in response to her.

Harry sighed. Of all the things in the world he expected, he did not expect Luna to have gotten an acromantula.

Though in hindsight, he probably should have.

...

Author's Note: Sorry if this is OOC for them, just I recall Luna being a fan of odd things and I figured that between an acromantula and a threstral, an acromantula would be more of the weirder choice. I need to re-read the books at some point.

I'm marking this post-Hogwarts since I can't really think of a good time frame during Hogwarts this could've happened. Sorry about that.

Also, I apologise if you aren't a fan of spiders and this upset you.

I hope you enjoyed the fic! Let me know what you thought!