While they will always want to take the lead with the other kids, they will probably be very generous and a lot of fun. They will love being with other children and will especially like to baby-sit when they are older. A cassette recorder with a microphone would also make a good toy. Amongst all the fanfare, Leo's can also be very organized, this combined with there leadership abilities, can make them very successful indeed. Leo's have a lot of pride and will take punishment very hard.
Immaturity can be a problem.
The power and leadership abilities that are present need to be used for a constructive purpose and not just for the furthering of the Leo's own ego. Giving to others is also an important lesson that Leo's must learn so that they don't remain so self-focused. But, watch out that younger children aren't completely dominated by your Leo the lion.