The content originally appeared on: CNN (CNN) - Sassy, hardy, and vicious: that's how yellow-eyed penguins are fondly described by the people who spend their days working with them. '(They) aren't as cute and cuddly as they look,' says Jason van Zanten, conservation manager at Penguin Place in the Otago Peninsula, New Zealand. 'They can give you a really hard slap.' Locally called hoiho, which means 'noise shouter' in M?ori, the yellow-eyed penguin is the largest of the penguin species […]