US readers: In a couple of months all of your friends might well be talking about Robert Popper. The hilarious fake science show that he and Peter Serafinowicz (voice of Darth Maul, flat mate Pete in Shaun of the Dead and douchebag Duane Benzie in Spaced) created, Look Around You, has been purchased for Adult Swim. (UK readers already know and love this comic duo) When that starts airing, everybody is going to be talking about how germs come from Germany and that the scientific name for water is H-20.

But you can get a head start on Robert Popper by getting to know his alter ego, Robin Cooper. Cooper is an obsessive letter writer, and the insane letters he mailed to people – and the hilarious replies – have been compiled in a book called The Timewaster Letters, now available in the US. The letters have to be read to be believed; the book had me red-faced and crying with laughter more than once. And the good news is that there’s a sequel in Britain as well as a novel about Robin Cooper.

Immediately buy The Timewaster Letters by clicking here. Well, immediately after you read my interview with Popper below.

Where did the idea come from to send these bizarre letters to random people?

I think as a kid I was always doing pranky phone, but weird ones really. Strange ones. I always enjoyed that. Several years ago, 1999, I got sent a brochure from a garden furniture company. I don’t have a garden, and I decided to write them back and tell them I was a designer of scarecrows made of beef. And then they replied back saying that they would like to see my designs. I can’t draw – as you can tell – but I always enjoyed drawing the stupidest things. I decided to make the scarecrows with a Roman theme and labled them with things like the Belt of Thebes and sent it off. They wrote back and said thank you for your scarecrow designs and I thought, ‘This is fun.’

At the time I was working in TV and I had an office and didn’t have much to do. I went to the library and found the addresses to all these weird British hobby groups and associations. I began showing my friends. I got addicted to getting letters. I used to get so much post.

Were you surprised that you got so many replies?

I was. Sometimes I would send a fairly normal letter first – they were always slightly mad, but would get more so as I went on. Then I started doing ones that were totally mental straightaway. I would say, ‘Well, they’re never going to write back to that,’ and then they would. I’m always surprised when they write back. Especially after they see my drawings. Or when they want to meet me to discuss a business idea. That was always funny and the terrifying.

You got published. Your drawings of ridiculous modern day maces got published.

My maces got published in a magazine. It was unbelievable! I’ve been published a few times. There was a lady who ran a fairy association and had such a mad newsletter. I sent her a drawing of a nine inch fairy who lived behind a blackberry bush. His name was Helr-Tahm. I love words like that which force people to have to type them out. The fairy was wearing a badge that read Trin-38. I asked what did it mean, and she said it was a wonderful story and asked if she could publish it so I said of course.

Is that sort of the highlight when it gets that real?

It’s amazing when it gets that real. I sent a letter to the Long Distance Walkers Association saying that I’m looking to walk from London to Sheffield. Now Sheffield is an industrial town in the north, and no one would really walk there. I think I mentioned that on the way I would be passing the famous windmills and all these made up landmarks that didn’t exist. I asked if anybody would be interested in coming along, and I got a letter from an older woman saying that she would love to go on a walk with me from London to Sheffield.

I think that what really fascinates me is that you followed this up with another book called The Timewaster Diaries, which really goes into Robin Cooper’s life.

This book came out a few years ago even though it’s just coming out in the US. Then I had the follow-up, Return of the Timewaster Letters, which was more madness. Then I was asked if I would like to flesh him out in a novel.

What is Robin Cooper like?

I like for people who read the first book to use their imagination, but he’s slightly deluded. In the Diaries book he comes across this brilliant idea which is a chocolate bar with a freshwater center. It’s a snack and a drink all in one. He spends a lot of time in his shed.

Looking at this book and some of the other stuff you’ve done I’ve noticed that you’re into building whole worlds, creating all-encompassing realities for your comedy.

I must say well spotted. It is true. We did a show called Look Around You with Peter Serafinowicz, and it was set in its own logical universe of fake science shows. We just created this new world religion called Tarvuism…

I’ve seen it. The website is unbelievably in-depth. [Click here to see how insanely in-depth it is]

We just pretended that our god is called Tarvu. We were writing it for an Adult Swim show in America, and while doing that we started writing our own mini-Wikipedia to help up, and it became quite addictive. We had so much information that we could never fit into a half hour program, so we set up this website. Now people have set up offshoot websites.

What’s the status of the Adult Swim show?

They got our budget, and we’re waiting. Who knows. We’d love to do something. We’re big fans of Adult Swim; they bought Look Around You.

When you and Peter write, what’s the process?

We have to get really excited about an idea. We do little things that we call our hobbies, where we aren’t doing it for money but for fun. Look Around You started as a short film we did for fun and it accidentally became a TV series. Same thing with Tarvu. We started writing the script for Adult Swim and then we decided to do a website. We have to get passionate about it.