It sounds like it's conference time with the parents and the cause of this child's anger be identified. Also, please look at nutrition. I love conferring with parents of children who are exhibiting unusual emotional responses to seemingly simple social situations.
Conferences are usually quite reflective and insightful.
If the child has a sibling who is unusually rough with him, this needs to stop. Toddlers are emotional and physical sponges. They become their environment. There is a child in my class who is extremely rough with his friends. I find that if my assistants and I continually demonstrate gentle touch to him, by example he learns.