Does the egg come first or the chicken that comes first?

You would need a chicken to make the egg but a egg to make a chicken! So this Question is impossible to answer.

Second answer

That depends on how you define the egg. If it is a chicken egg, then a chicken would obviously have to come first in order to lay it. If you mean eggs in general, then eggs were around long before chickens. The first creatures to lay eggs on land were lobe-finned fish, fish with usable lungs and a means of locomotion outside the water. A group that split off from these fish became amphibians. Evolution continued down the line as groups split off to become reptiles, such as dinosaurs. Predatory dinosaurs known as Theropods eventually gave way to birds. The modern chicken is believed to be descended from wild jungle fowl active in South, East, and Southeast Asia. In conclusion, fish, amphibians, and reptiles laid eggs millions of years before the appearance of chickens.