Over 17,000 animals were weighed and had their height taken by the Zoological Society of London (ZSL) on Wednesday, reported ABC News. Hannah McKay/EPA / Via abcnews.go.com Whether big or small, every critter had their measurements recorded and added to an international database for zoos all over the world to see. Neil Hall / REUTERS / Via abcnews.go.com It was important for all these cute and cuddly (well, not all of them) animals to have their yearly check-up. "We have to know the vital statistics of every animal at the zoo – however big or small," explained Zoological Manager Mark Habben. oversixty.com.au / Via abcnews.go.com "This information helps us to monitor their health and their diets and by sharing the information with other zoos and conservationists worldwide, we can use this knowledge to better care for all our animals." While some of the critters didn't mind going to the doctor, others did. In fact, the penguins were FOOLED into having their weights taken. EPA/HANNAH MCKAY / Via abcnews.go.com While the penguins were on their continental breakfast line, they had to step on the scale in order to get to their meal. Fear not, Mr. Penguin! You aren't as hefty as you think you are. Hannah McKay/EPA / Via abcnews.go.com The lions and tigers were encouraged to stand up tall, by having their meals held over their heads. All in all, it was a successful weigh day. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Via facebook.com Good job, everybody!