The monsters enter the Grails web framework! Jonas Nordstrand has written a plugin that opens the door to them. This is what he says about it:
A grails implementation of MonsterID: a method to generate a unique monster image based upon a certain identifier (user id, email address, whatever). It can be used to automatically provide personal avatar images in blog comments or other community services.
You can find this plugin (as usual) on grails.org.