The lion is a large member of the cat family. It attacks with its claws and bite. They hunt in groups called prides generally with one male and multiple females. They use some basic group tactics, so making them moderately smart in AI terms would be appropriate. They can be quite stealthy. Young males without a pride will also hunt together. The aspect of lions perhaps best suited to roguelike mechanics is the mighty roar of the lion, which could be treated as a fear-producing effect or even a minor sonic weapon.