Mark 10 is the grandson of Ben 10.Mark 10 is about 10 and a half years old and at that time Ben is 69 and a half and has white hair and glasses.Mark has red hair and freckles.He often wears a t shirt that looked like Ben shirt only it was yellow and black instead of white and black.His t shirt doesn't have sleeves. Mark 10 got the omnitrix and Mark 10 also wears a green hat that says alien hunter and he also wears black shorts.