I think you can imagine everyone has ankle weights on, or technology, and there's a reason that people aren't floating around. But I also liked this idea that in this world, people forgot they can swim. The modern world weighs you down, there's always emails to check, you've gotta go to your job and pay your mortgage. You're not really thinking, "Oh, yeah, I can swim around." BoJack discovering it is a big deal, and kind of fun.

Daniel Radcliffe was actually a fan of the show and excited to be on it. Some of it is we've gone long enough that we're legitimate. Even if they don't know the show, they know we are a show and not some weird thing that's going to go away. Also, the more celebrities we get on BoJack show, the more it feels like a club to be in: "If Naomi Watts will make a fool of herself, I guess I can make a fool of myself, too."

We often ask, "Do we have enough humans?" Because it's always fun to come up with an animal in show, but it begins to feel like overkill.

Anything is possible in this universe. It could be that you turn the chair around it's just a glove handcuffed to a bomb, like in Inspector Gadget.

In a certain way, sometimes it does feel like we say goodbye to a character, and we don't want to bring them back unless we have a good reason. We left the door open if we wanted to use him more. I always think it's better to leave the audience wanting more.

I want each season to feel new and special. I don't want it to feel, "Oh, more of this." That's something that's easy to do in the first three seasons, and harder to do as you go. I'd rather err on the side of blowing up everything and being like, "Why did you do that? There was more story to tell there," and moving the family to Mexico like on Weeds, instead of people going, "Oh, we've seen this already. We're tired of this."

It was fun figuring out the science of the world as much as we wanted to figure out, and then playing fast and loose in other places. Which we do with our show in general. One of the things we love about the BoJack Horseman show is that we can always fall back on, "It's a ridiculous cartoon." And it is! It's a serious, relationship-based grounded character tragedy, but it is also a ridiculous cartoon.