1)post a pic or tell us how big your snake is
2)Feed you snake if he is hungry
3)Feed several mice at a sitting (or as muny as the snake will eat) and wait until the lumps dissapears and then feed again.
A wild king eats large meals so it has the ability to digest them. They eat snakes, lizards and basically animals with more calcium and protien than a small mouse. You should get your king to grow as fast as possible by getting it on larger size mice. Pinkies and fuzzies have hardly any nutrition and are mostly made up of water and fat. Also a lot of people don't realize that their 20" king can eat adult mice and keep feeding too small a meals.
Once you snake gets full size or slows down you can back off feeding it as much as it will eat. Fat deposits are not likely in colubrids. However you might get a differing opinion from some other hereas to what "fat" is. IMO fat is much more likely in females than male colubrids. Thats because females that are breeding have a propensity towards fat for egg laying. Feed a female as much as possible through the egg deleopment stage and then again feed as much as possible right after egg depositation until a healthy bodyweight is acheived.
The only time fat is bad is when the sperm cannot get to the eggs of the females because of to much fat in the ovum. The ovum is where fat deposits occur. This is much more likely in boids than colubrids.
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"Yeah ya told me, and ya wrote it down too. But how the hell am I supposed to remember!"