How do you get Blue Yoshi?

I'm curious, how exactly do you acquire the elusive Blue Yoshi? Is it through a special in-game event, a limited-time offer, or perhaps a rare drop from a certain boss? I've heard rumors of its existence, but I'm still in the dark about the specifics of how to add this unique character to my collection. Could you enlighten me on the process, and any tips or tricks that might help me on my quest?