10 of the world's deadliest animals You don't want to cross paths with these creatures. Sometimes distinguishing between furry cuteness and pure destruction is not an easy task. In fact, many of the animals kingdom’s cutest critters also happen to be its most prolific killers. You think that cute little puffer fish is adorable? Will you hold your breath as you reach to pet it? The answer is yes. Forever. Here are some of the world's deadliest animals.