qT=2&tQ=Hippos have been known to flip boats that come too close to their young.&tC=True|False&cC=1&fB=Hippos are the second heaviest land animals in the world (elephants are the heavier). Males can grow as large as 5,500 pounds and both sexes will fiercely defend their young from potential danger.<br><br>For example, hippos have been known to attack boats that come too close to young, sometimes with fatal results.