In order to hold its head up, it would have to be conscious. If it were conscious, it would be reacting to the lion bites. I think it's more likely it got locked in that position by rigor mortis, which can start very soon after death in hot climates. It may not have originally even been in that sitting up position, who knows...i'm pretty sure that hippo is alive...
i googled how much a hippo's head weighs and i think his head is way too heavy for those cats to bother holding it up...View attachment 709735
sorry, i probably could have edited this pic better ...
