Cut the top ½ inch off the top of the cooked egg and cut off a small slice off the bottom to make it sit upright. If you cut it at a slight angle it will make the face look slightly up. 

Carefully remove the yolk. Do not break the white. You may need to cut a deeper slice off the top to get to the yolk, which is ok. However, do not cut down to make halves. There should still be at least 2/3 of the white to make a face. Reserve the top cut out piece of the white to use as a nose.

Press the yolks through a fine mesh sieve into a small bowl. 

Add 3 tablespoons of the mayonnaise, the mustard, jalapeño pickle juice, salt, and the white pepper. Mix to combine thoroughly; it should be very smooth with no lumps. 

Stir in the drops of blue food coloring. The color of the mixture should be a very light green. If the consistency is off you may add more mayonnaise. But, it should still be a fairly firm filling. It needs to be firm so you can shape and carve veins.

Place in a small plastic bag with a corner cut off or a small piping bag and reserve. 

To make the faces: with a sharp knife cut a slit 1/3 inch in the center of “face” straight down. On either side of the slit cut half circles at a very shallow angle being careful not to cut through, leaving them as a flap. 

Cut very small wedges from the reserved top piece of the egg white. Gently squeeze the egg white face to open up the slit and insert the wedge to make a nose; the pressure of the slit closing should hold the wedge in place.

Cut small thin ovals from the sides of the black olives. Using the tip of a knife, carefully hold open the flap of white on each side of the face and slide in the oval of black olive to make the eyes. 

Pipe the filling evenly between the eggs.

Wet your finger either with water or the juice from the black olives. Press the filling down to smooth it out into a brain shape. Using a wet spoon or knife, further shape the “brains" into two lobes and a few lines for veins.

In a small bowl water down the Sriracha slightly to make a brushable “blood”. Carefully brush just the “brain” part.