They do not. I think mine evolved from happiness, but the Department Stores also sell an item that can speed up the process. I'm not quite certain how it works, however.

And what does it evolve into?

Milotic. Quite lovely creatures, as long as you've no fear of sea serpents.

Sea serpent?

One that is smaller than Gyarados, but also more elegant. Would you like to see what they look like?

Yes, yes please!

Very well. Leviathan, please come here for a moment.

[And there she is, in all her serpenty glory.]

She really is something to look at. Wow.

That she is. I always knew she'd turn out to be the prettiest in the region.

[He found her beautiful from the moment she hatched, mind you.]

Well... Until mine evolves.

...No, I'm quite certain Leviathan will keep her title.

We'll see about that.

We undoubtedly will, as long as you take good care of it.

You'll see, you'll see. Just be prepared for the "I told you so."

Of course. I've no doubt you'll have no trouble compensating for the two-year headstart.