i think you should not be much worried at this behavior of your child as at this age of around 2 years, every child develops feelings of me and mine and the primitive instinct of beind independent i reflected in his aggressive or sometimes violent behavior.
the best you can do is to respond to any such behavior of your child immediately to try to make him understand that what he has done or is going to do is not good or acceptable, and try to reinforce same thing again and again with similar attitude of non acceptance.
you can even try some punishment like time outs for him, but dont forget to reward him for his good behavior. this phase generally passes off as the child grows and and is able to differentiate between good and bad behavior.
as you said he is otherwise normal and loves books of animal etc, and this is qiuet reassuring that there is nothing wrong with him at present.
but if you think that things are going out of control you should not refrain from taking professional help from a child psychologist
or a pediatrician
hope you ve benefitted from my reply
thanks for the query