My choosen creature: Turritopsis Dohrnii - the immortal jellyfish, it's a species of small biologically immortal Medusozoa found worldwide in temperate and tropic waters. It has a unique ability to revert back to its younger polyp form after reaching its fully-grown state, and thereby starts it's life cycle again.
Q&A: I humans had this specific animal's power, how would it change our daily lives? If we were like Turritopsis Dohrnii (immortal jellyfish), we'll live forever, for if we reach adulthood, anytime we can regenerate our whole body, back to a first-born baby and start a new life again.