Although our banana slug compatriots get to switch sex on a whim, most females in the animal species are pretty much left to gestate and birth their offspring. Most of them -- humans included -- at least get to find a fairly comfortable position to push a living being out of their birth canal.
But giraffes give birth standing up.* Yes, not only does it sound unnecessarily uncomfortable (which it probably isn't, if they all do it, right?), but remember what animal we're talking about here: The giraffe's birth canal is 5 feet (1.5 meters) above the ground [source: National Geographic]. So yup, baby giraffes suffer a pretty decent smack on their first landing. Perhaps worse for the giraffe mom, their little ones start running about 10 hours after birth [source: National Geographic]. These kids go from zero to hell-raising toddler in no time.
*We should note that some humans prefer to give birth standing up, too.