Prankster

So I had to post this up.
First the disclaimer: We do not have any idea where my son got this idea. It is not in any shows that he watches, etc.
My almost 5 year old decides to take a red marker and color all over his hand and fingers. He then goes into the kitchen where my husband is and starts to hold his hand and say, " Daddy! Look at my hand! Ow!!"
My husband has the normal reaction any parent would seeing a red hand, he started freaking out.
My son then starts laughing and says it's okay, it's just marker.
So my question is, when do children learn to be pranksters.. I remember doing such things as a kid but it facinates me when a child can figure it out themselves.
That was a good chuckle..