No, but just because a hippo is large and fat, doesn't mean it isn't hard either. They are grumpy aggressive motherfuckers.
'Crocodiles are particularly frequent targets of hippo aggression, likely due to the fact that they often inhabit the same riparian habitats as hippos. Crocodiles may be either aggressively displaced or killed by hippopotamuses. Hippos are also very aggressive towards humans, whom they commonly attack whether in boats or on land with no apparent provocation.[60] They are widely considered to be one of the most dangerous large animals in Africa.'
Pound for pound hardness. Hippos SHOULD beat up Crocs.