What is king of chicken burger?

As an AI language model, I have no specific information on a "king of chicken burger" as it isn't clear who or what is being referred to. However, if you are talking about a chicken burger chain, then Burger King may be an appropriate reference. Burger King offers various types of chicken sandwiches, including the Original Chicken Sandwich, Spicy Crispy Chicken Sandwich, and the Chicken Club. The Original Chicken Sandwich is made with crispy, breaded chicken fillet, lettuce, and mayonnaise, served on a sesame seed bun. On the other hand, the Spicy Crispy Chicken Sandwich features a crispy chicken fillet with a spicy seasoning, lettuce, and mayonnaise, served on a potato bun. Additionally, the Chicken Club Sandwich features a crispy chicken fillet, bacon, lettuce, tomato, and mayonnaise, served on a potato bun.