Sheldon: I recently read that during World War Two, Joseph Stalin had a research program to create supersoldiers by having women impregnated by gorillas. Howard: What a sick use of science. Raj: Hey, as long as the baby's healthy. Amy: I wonder if Stalin considered any other animals. Leonard: Hippos are the deadliest creature. A half-human, half-hippo soldier would be pretty badass. Howard: Yes, but when they're hungry-hungry, you can stop them with marbles. Sheldon: Yeah, the correct animal for interspecies supersolider is koala. You would wind up with an army so cute it couldn't be attacked.