differences: 1.smiley is 6 feet tall while jeff is possibly the size of the average human male
2: smileys body is a bit better then jeff
3: jeff has more killing experience having started in his teen years
4:smiley lives in the cow slaughterhouse he worked at (which is abandoned ever since he killed some workers) while jeff iis in abandoned mental hospital
5:smiley uses many things to kill while jeff uses only a knife and lighter
6:jeffs face has a large smile due to him using a knife to carve the smile in his cheeks while smiley just has a large mouth
7: smiley wears a grey hoodie while jeff has a white one
8:smiley attacks at anytime of the day while jeff attacks at night
9:smiley attacks you within a hour of seeing his face while jeff will kill you with no wait time