Hippos
Hippos might seem slow and sluggish, but they are neither of these things. There have been several recorded cases of hippos capsizing small boats when they feel like their lives are in danger. This photo was taken in 1995 and shows French zoo director Jean Ducuing messing around with Komir the hippo. Sadly, Ducuing was killed by Komir when it saw an opportunity to make a break for it and sped out of its enclosed habitat.