Rihanna joined the Flintstones-themed birthday party of her cousin Noella Alstrom's daughter Majesty in an orange-and-black costume as the R&B star introduced herself as "Thotty Pebbles."
Doing her best to make her 1-year-old niece's special day the best, the "American Oxygen" singer sizzled in an asymmetrical off-the-shoulder outfit that showed off her toned midriff.
Accessorising her look with bones, the "Diamond" singer looked similar to toddler character Pebbles on the popular Hanna-Barbera cartoon.
The Grammy-winning star attended the bash along with some close friends including Jennifer Rosales, who dressed up as "Ratchet Wilma," and Melissa Forde.
The lively event was documented by Melissa in several videos which were later uploaded on her Instagram account.
