Hope you enjoy 😉 
Credit : 
Disney 
Hasbro
Artis
Casting : 
Fluttershy as Ariel
Princess  celestia as king triton 
The mane 5 as the sisters of Ariel  
Spike as flounder 
Discord as prince Eric
Twilight as Sebastian 
Pinkie pie as scuttle
Starlight/chrysalis as Ursula