In the Lord of the Rings prequel they had a wizard who rode a sled pulled by six giant rabbits as fast as horses.
As soon as I saw it; I decided I want some.
How would I go about creating such giant and fast rabbits, assume I have about a billion USD to spend.
First thought in my mind is that rabbits are probalby not suitable to be bred up into draft animals. They tend to be sprinters instead of distance runners.
I would start with a large hare, such as the American jackrabbit (nomenclature not withstanding, they are different though related animals). They do breed quickly, so intense selection of the larger specimens each generation and strict line breeding should get you riding or draft sized within fifty years. (Maybe you can splice in mule deer genes and actually create the Texas Jackalope.)
I think by the time you get them big enough for 6 of them to competently pull a sled, they’re not going to look like rabbits any more - You can either have big, non-athletic rabbits (like Flemish Giants), or big athletic animals that aren’t very rabbit-y (something more closely resembling a deer, perhaps)
The Lord Of The Rings prequel? Do you mean The Hobbit: An Unexpected Journey?! 
Edit: You do realize The Hobbit was written first, right? Originally it was a standalone novel, but Tolkien wrote more.
Like a Jackelope maybe?
Suuuuure. Next you’re going to tell us that Paul McCartney was in a band before Wings!
“Wings”? Sir Paul was in a band?
Yes – it was him, Gandalf, Saruman, and Radagast. There are rumors of two others, but I think they died before the band got big.
Their big hit was “When I’m 64,000.” In the cartoon version, they all get long grey beards.
I’m skeptical that 50 years will get you there by just breeding. Selecting larger specimens will only get you as far as is already in the gene pool, then you’ll be stuck until you get the right random mutation(s). Splicing in genes from some larger relatives (assuming there are some related closely enough) would help.
Whoever the other two were, I know they weren’t balrogs. Balrogs don’t have Wings.
For humanity’s sake, do not conduct this experiment or we’ll end up experiencing the terror of Night of the Lepus!
As I’ve saud before:
“As Iluvatar is my witness, I thought Balrogs could fly!”
Horses were about the size of rabbits at one time. I don’t believe they possess the genetic material to allow them to reach that size. It might take a few million years of selective breeding waiting for mutations to come along. Genetic engineering would greatly increase your chances ofseeing it in your lifetime.
Europe has some huge freaking hares. Make Jackrabbits look tiny.
When I was in Austria, I saw some hare hunters (Hassjaegeren?) with their bounty. Those things were huge…at least as big as a smaller husky. They had to hang them by the back legs at least 5 feet high or so to keep them from dragging the ground.
Give them some Red Bull.
The Capybarra should do it.
It’s a rodent that is as big as a large dog (picture), They aren’t known for their speed however(they only sprint 15mph)
Rabbits (and hares) are not rodents.
Looks to me like hares would be a much better choice than rabbits. Hares can run pretty well, while rabbits tend to have a lot more vertical in their locomotion. A carriage or sled pulled by rabbits would be a rough ride.
I think if you bred rabbits up to the size where they could pull a cart, you’d have animals that look a lot like deer.
That was the opinion of Dougal Dixon, who wrote the book After Man as well:
