I only have one snake I would consider aggressive. He was a doll before he came home but after I set him up he's been aggressive (tracking my movements, striking, etc).
The corn snake that bit me has never bit out of aggression. It was a simple case of mistaken identity. My finger was warmer than the mouse, smelled like a mouse, so she figured it was a mouse. She quickly realized I was not a mouse and let go, and struck the mouse and ate. The pastel ball python I was holding was in shed so could not see me. He also was not mine (pet store) I ended taking home his brother. The carpet python was also not mine (pet store). The pastel male (brother to the one that bit me) was aggressive from the time we brought him home though with handling he has calmed way down. I can now reach right in and pick him up, even if he's in shed.