You can get this in the first run of Mermaid Falls, the third level of the game.
At the end of the second area of the level, just after going over a screen after a long climb through rings and defeating two techno grunts with pots below in small alcoves, you will see a special pot at the end of an indented pocket. Hit this pot to get the snake lady to come out, like a snake charmer.
Buy and/or make any trade with her to unlock this achievement.
It's also worth noting this is where you can get the Gem Jug dance here by buying the Warp Dance and trading it for the Gem Jug dance. You can use the Gem Jug dance back in Scuttle town in the bathhouse for infinite money.
The walkthrough by PistolMcAwesome
does a nice job of laying this out for you: Shantae: Half-Genie Hero Walkthrough
(Page 5)Shantae: Half-Genie Hero Walkthrough