In the large bowl of a stand mixer, or with a hand mixer, cream the shortening, brown and white sugars together until fluffy.
Add the corn syrup, water and vanilla. Beat well until fluffy again.
Add the flour, soda, salt and oats and mix well.
Carefully fold in the the rice krispies, coconut and chocolate chips by hand.
Add the rainbow jimmies last. Mix these in carefully, because they can get easily crushed.
Scoop dough on to a parchment lined baking sheet and bake until just browned on the tops. (2 Tablespoon-sized balls for mini-monster cookies, or 1/4 cup sized balled for mega-monster cookies. Flatten the big monster cookie dough balls a bit.)
Bake 8-10 minutes for mini-monster, 13-15 for mega-monster. Makes 24 mini-monster cookies or 12 mega-monster cookies.