A Reason to Have a Kid?

Far as I can tell, there aren't a lot of good reasons to procreate other than for the fun of naming something other than a plant or a dog (Levi and I are thinking about getting two more terriers just so we can name them Rosencrantz and Guildenstern), and in order to play your own version of Conan O'Brian's "If They Mated". For example:

I always thought there were just those two reasons to have children. But this had me thinking there might be three reasons:

Until I remembered you could just make a big shark sleeping bag and put an adult in it.