A.,
As mother of older kids ( 21, 19, & 16), I remember how much fun it was to expose them to all sorts of family entertainment. However, as a season ticket holder for Dallas Summer Musicals (which is the group sponoring the Lion King's performance) for many years, I've witness first-hand how difficult it was for both the parents and kiddos to enjoy a theatrical performance when the kiddos were not really ready to sit still (and quiet) for that long of time. While, the Lion King is a wonderful performance (I've seen it twice and have tickets to see it again this Fall), and I would encourage any one who's interested to go to the upcoming performances, it is probably going be too much for your little guy this time around.
Now, when my kiddos were that age, we truly enjoyed the Dallas Puppet Theater. I'm not sure if that venue still exists. I know there was a theater at NorthPark for Kathy Burke Puppets. You might try and determine if that is still around.
R.