In a large bowl, blend together 10 ounces of softened cream cheese along with the guacamole, salt, pepper, and garlic powder.
Add the cilantro (or basil paste) along with a few drops of green gel color until you achieve your desired shade of green.
Spread the green guacamole dip in the center of a large serving platter in a modified diamond shape, making sure to give him large cheeks and a pointy chin.
Use a damp paper towel to clean any smears on the platter and to give the Grinch a nice, clean edge.
Use a spatula to angle off the top of his forehead so the Santa hat will sit on a jaunty angle.
Smooth the guacamole with the spatula. Set aside.
In a medium bowl, blend the remaining cream cheese, pimentos, smoked paprika until smooth.
Stir in enough red food gel until you achieve your desired hue, and then mix in the sriracha (if desired).
Spoon the red cream cheese mixture on the side where you angled the Grinch head and use a spatula to smooth and form the mixture into a Santa hat.
Gently press cauliflower florets to form the fur trim of the hat, and place them around the base of his face to form the fir trim of his suit.
Use a paring knife to cut semi-rounded pieces from each of the yellow zucchini slices.
Press a pimento piece in the center of each black olive slice.
Gently press the cut zucchini slices into the Grinch face, on a slight angle.
Place the pimento and olive slices on the zucchini slices to form the eyeballs and pupils.
In a small bowl mix together the mayonnaise and a few drops of black gel food color until you achieve your desired hue.
Spoon the mayonnaise mixture into a large zip top bag, or a piping bag.
Snip a small hole in the corner of the bag and gently (and consistently) squeeze the bag to pipe out the Grinch's eye lines, mouth, and cheeks.
Snip a larger hole in the corner of the bag and pipe some thick, bushy eyebrows (on angles) over the very tops of the zucchini eyes.
Finish by placing a small broccoli floret right below his eyes, for his nose.
Refrigerate until ready to serve.
Serve with crackers, chips, vegetables, and roast beast.