Happy Aquarium: Walrus Referee and Football Seal join the team
Zack the soccer-playing lion cub is now joined by Russ Referee and Diego the Football Fan in Happy Aquarium. Both Russ and Diego are animated critters that cost premium currency to buy. Russ taps his foot, blinks his eyes, and blows his whistle. While Diego is more like Zack, and carries a hot pink soccer ball on his head with which he performs tricks in the tank.
Russ is also a Limited Edition character, so if you've got 24 Pearls or 20 Facebook Credits (the equivalent of $2 USD), you should grab him ASAP, cause he won't be sticking around the shop forever. You can find him under "Specials!" star tab, under the subcategory "Premium", while Diego is with Zack in the "Tank Mates" tab, and goes for 48 Pearls or 40 FB Credits ($4 USD).
Given the game's recent premium currency increase for leveling up, these characters should now be easily affordable for high-level players.