The largest amount of yolk is found in the eggs of birds, also known as Aves.
Birds lay eggs that are designed to provide nourishment for their developing embryos. The yolk is one of the main sources of nutrition for the embryo and is rich in proteins, lipids, and other nutrients. In bird eggs, the yolk is typically large and round, and makes up the majority of the egg's volume.
In contrast, the eggs of reptiles, amphibians, and fish often have smaller yolks that are not as rich in nutrients. These eggs are usually designed to be laid in water or moist environments where the developing embryo can receive nutrients from the surrounding environment.
So in short, if you want to find the largest amount of yolk, look for bird eggs!