First I thought the lizards are playing but then I noticed one grabbing & biting anther’s throat. I was on my way hiking so I stopped for a few minutes because it was quite entertaining. I watched for about 15 minutes and couldn’t predict the winner; Although the smaller one looked more aggressive. On my way back both were gone and I didn’t see any dead bodies.  I don’t know what kind/species of lizard they are. I have seen them around so I assume they are popular here in Los Angeles, California.