The last two and a half minutes of The Lion King never fails to bring a nostalgic lump to the throat, but the reality is probably even more upsetting.
As Simba ascends Pride Rock and assumes leadership of the pride, his majestic roarheralds a reign of terror that is soon about to begin.
For a start, the cute, seemingly monogamous, relationship between Simba and Nala would beslightly more one-sided, as the alpha male in a pride of lions will mate with all of the females, sometimes every 20 minutes.
Secondly, leadership struggles in the pride of lions are almost always bloody affairs. When a new male takes charge of the pride (which happens twicein TLK), one of the first things he will usually do is kill any cubs under 9 months old. It is estimated that as much as a quarter of the cubs that die in their first year are victims of infanticide.
Doing this brings the females into heat again so that he can put his own little buns in their ovens and begin his own bloodline. You can be sure as hell that Scar did this when he took over, so the virtuous Simba would probably do the same, taking out all of the little Scars running around his castle.