"A Sloth? Really? My Animagus form is a SLOTH?"
"Come on, dude. Everybody loves sloths."
"That's not -- look, I wanted to have an easy mode of transportation. Like a dog or a wolf or a horse. All those things can run really far. But I got precisely the opposite of what I wanted! Look at this!" *Poof* "Oh look at me, I can move one centimeter per hour, I can eat leaves, aren't I wonderful?" *Poof* "This whole thing was a fucking waste of time."
"Hey, you're thinking about your disadvantages instead of your advantages."
"Excuse me? Advantages? What advantage could there possibly be in a FUCKING SLOTH?"
"Their claws are really sharp and they can do someone serious injury then they finally decide to cut loose."
"Okay..."
"And nobody takes them seriously so your enemies can get really close before you strike."
"This all seems really situational."
"And you can infiltrate muggle zoos."
"Still situational."
"And you can climb tricky surfaces."
"Yeah, yeah, great. But here's the other thing: being an Animagus is about being inconspicuous. Have you forgotten that we're in the Highlands of Scotland?"
"Look, the whole thing is based on your personality. You're really slow until you decide to move fast and you're really relaxed until something really big happens and then you're always out ahead of me in battle. The magic doesn't care what you wanted or what makes sense."
"Clearly. I just can't figure out how to work this to my actual advantage."
"I have an idea. Sloths can climb really well, right?"
"Yes..."
"And they blend into concrete."
"Okay..."
"We could do a heist."
"We?"
"I mean, I got the spider form, and that's incredibly vulnerable unless someone is watching my back."
"Fair enough! Still very situational, but useful. Let's go heist a zoo."