That is usually called a cutler's anvil. Jantz and some suppliers sell them. You can also find them at Harbor Freight. The bick ( horn) or the heel can be ground thin for folder work like the one shown by Tiguy. A google search of the internet will show lots of photos and some sources. They are pretty easy to make from a small block of 4140. Saw and grind to the desired shape and then HT.