my four year old child has an alias?

we ate dinner at pizza hut last night, along with a large gathering of biker folk. tim knew several of the bikers. not from arresting them or anything; just knew them from around, you know?

timmy was getting restless and wiggling around, acting up a bit, so tim pointed to one biker and asked, "do you want me to have that guy over there come and give you a talking to?" i gave him the most evil dirty look, so he changed it up a bit and asked, "would you like me to introduce you to that gentleman over there? mr. presnall?"

well, timmy is no fool. he got very still and answered, "i will tell him my name is shep o'brien."

am i bewildered that my just-turned-four child has already developed an alias, or am i proud of his sweet mad self-preservation skillz?