Phua Chu Kang's mole is actually made of papier-mâché. It is molded into a ball, painted black, and attached to his face with cosmetic glue.
Gurmit Singh once ate his prosthetic mole, after it fell into a bowl of bubur-chacha which he later had to eat for a scene.
The season started with Phua Chu Kang wearing black boots. One day, the wardrobe team misplaced his black boots and gave him yellow boots instead. That worked very well, and became an iconic element to his look.