You have to go back and think about your high school bio class when you learned about genetics, Gregor Mendel’s pea plants and recessive vs dominant traits. If you have a snake that is a “het” it is heterozygous for a specific trait, which means it has one copy of gene that makes that trait, and one normal/wild type copy (two copies of each gene in total because chromosomes come in pairs). You will only see that specific trait if there are two copies of it in the same animal, because it is recessive.
If you cross two hets, each with one copy of the normal/wild type and one copy of the trait you want (such as piebald), you can draw a basic punnett square (like the one I quickly whipped up below) to figure out what the offspring will be. 1/4 will have two copies of the piebald gene, 1/2 will be hets, and 1/4 will be normals. However you cannot visually tell the difference between the hets and the normals, so each offspring that looks normal has a 66% chance of being a “het”
