Cut a small piece off the bottom of a tomato so the bottom is flat, reserving the piece. Cut the remaining tomato in half. Thread the bottom half of the tomato onto a skewer and slide it down.
Thread a mozzarella ball onto the skewer for a head and slide it down to meet the tomato piece (Santa's body). Thread the top half of the cherry tomato onto the skewer for a hat. Poke the skewer into the center of a cucumber slice to stabilize it so the skewer will stand. Repeat with the remaining tomatoes, mozzarella balls and cucumber slices.
Combine the cheese spread with the milk in a small bowl and stir until creamy and pipeable. Transfer to a piping bag or resealable plastic bag. Snip off a small piece at the end of the plastic bag to create a small opening.
Pipe a zigzag triangle of cheese at the bottom of each Santa face for a beard, extending onto the bottom piece of tomato. Pipe the cheese around the bottom of each Santa hat, then pipe a small piece at the top of each hat.
Cut a small sliver off the rounded edge of the reserved tomato bottoms and place one on each beard for a mouth. Put on 2 black sesame seeds for eyes.