Safe to say Serena Williams' 5-year-old daughter is a big fan of "The Little Mermaid" ... Olympia LOST IT after she got a Halle Bailey "Ariel" doll, and the entire adorable reaction was captured on video!
The video, which was shared on Olympia's Instagram, shows dad Alexis Ohanian handing his daughter a package from Amazon.
"Momma and poppa wanted to get this for you," Ohanian said.
When Olympia realized it was Bailey as Ariel, she (literally) jumped for joy ... and started screaming hysterically.