The large hippo is an aggressive animal; old scars and fresh, deep wounds are signs of daily fights that are accompanied by much bellowing, neighing and snorting. Hippos have developed some ritualized postures the huge
open-mouthed "yawn" that reveals formidable teeth is one of the most aggressive. With the long, razor-sharp incisors and tusklike canines, the hippo is well-armed and dangerous.