jmc

There are 12 ways to select the first crayon, 11 ways to select the second, 10 ways to select the third, and 9 ways to select the last. However, since order does not matter, we must divide by the number of ways he can draw out the crayons, which is $4!$.

The answer is $\frac{12\times 11\times 10\times 9}{4!}=\boxed{495}$ ways.