Is it ok to be angry at kids?

Dear Jane

I had to share this experience with you from one mom to another. I have two children a little boy (6) and a daughter of (11)

Anyway my son has a friend who I cannot stand. This child (let's call him Sam) is rude, manipulating and is a bully. Last week I went to collect my son from school and was stunned when I saw a drawing that was clearly his (my sons) up on the classroom pin board  as he always draws this particular thing in a certain style, however this obnoxious child had his name on the drawing. When we got to the car I asked him who drew it and he went quiet. When I gently asked again he admitted that 'sam' had made him hand it over and proudly took it to the teacher to be pinned up.

As a middle aged woman who went to varsity and is by nature a very chilled person I am so enraged whenever I see this child let alone have him in my home. Is it normal to dislike and have anger towards a child?

Kind regards