Slice the avocados in half. Remove the seeds and scoop the avocado out of the skin into a bowl. Mash with a fork stir in the salsa. Set aside.
Remove all of the leaves from the cauliflower and remove the thick stem, leaving a nice hollow area with the outer part of the head intact. Use toothpicks to hold it together if it starts to fall apart.
Place the cauliflower upsidedown into a small bowl, so that the hollow is facing upwards and most of the cauliflower is up out of the bowl. The bowl is just for stability. Fill with the avocado dip. Decorate the white ''brain'' by weaving thin strands of red roll-up between the florets to make veins and arteries. I wrap the bowl with cheesecloth and decorate with red food coloring to make it even more horrific!