Five Creatures That Prove Life Could Exist On Other Planets (Or In Space)

This post got my imagination going: From io9, Five Creatures That Prove Life Could Exist On Other Planets (Or In Space). An excerpt:

Want to know what life will look like on other planets? Look no farther than these five creatures, who are already prepared for life on Saturn's moon Titan - or in the hard vacuum of deep space.

Unlike humans, with our pesky need for things like oxygen and sugar, some creatures are more flexible in the habitats where they feel comfortable. Here are five lifeforms who are prepared to live on other planets right now.