Had lunch with fried chicken, wings was slightly black burned. when i poop, my stool color was black. is it caused by chicken? no any other symptom.

Unlikely: Generally, black and tarry stools happen when there is cause of upper GI bleed. Here the hemoglobin undergoes chemical reaction leading to change in color. A common cause for this is ulcers. They can be caused by medications (advil (ibuprofen) or motrin) or infections (H. pylori). For now, I would suggest monitoring for other symptoms. It may be absolutely nothing because you have no other symptoms.