Mandai Wildlife Reserve has unveiled a $15,000 organic, sugar-free durian cake for a gibbon, despite the primate’s visible desire to hurl faeces at the PR team.

The three-tier masterpiece, crafted from imported Himalayan kale and artisanal ants, costs more than the combined CPF savings of the entire maintenance crew.

Zoo officials claim these extravagant celebrations are essential for the animal's mental health, which is apparently more fragile than a fresh graduate’s ego during a performance review.

"Wah lau, the monkey eat better than me sia," said local witness Tan Ah Kow, while staring at his sad, watery porridge.

"I work ten years also no cake, this fella just hang there shake leg get buffet, damn heng ah."

The birthday boy celebrated by immediately urinating on a group of primary school students from a height of ten metres.

Mandai executives confirmed the urine is "holistic" and will be sold in the gift shop as a $45 detox mist.