I wouldn't recommend this place as a destination but if you're already at the Mandalay Bay...and someone in your group is taking a dump I would definitely check it out.
It'll take 20-30 minutes, tops. $18/adult and $12/child.
I had high expectations for myself and the additional burden of responsibility given I was the only person (out of 7) who wanted to go. Needless to say, I owed them all a drink.
Highlights include: komodo dragon, stingray and horseshoe crab petting exhibit, and the hammerhead sharks.
Couldn't help but feel sorry for the creatures since their space was so confining.