Pattern for a Franenstein head?

My 5 year old son informed me today he wants to be Frankenstein for Halloween. Cool! Then I started looking at pics and asked myself how I’m going to give him a “tall and flat head”. Well, in comes knitting. Surely someone out there has a pattern to extend my son’s head and make it green and flat. Any patterns? I could probably fudge it but I’d prefer a pattern if anyone has one. Thanks!!!
Found a couple for sale thru Ravelry. The 2nd one gives the flat top look you want. Just looking at it should give you an idea how to get the shape you want.

Here’s a link outside of ravelry to the one:

Sort of make a round dishcloth for the top of the head, then pick up stitches around the edge and make the sides as loog as you think it needs to be.

Man, I LOVE the second one but it’s a crochet pattern. Drats. It would be perfect and I love the “bolt” choker that goes along with it. Too cute. It’s giving me ideas at least!