Aang had already reached the tiger cages, and was waiting for them impatiently, rocking back and forth on his heels with a huge grin on his face. "Slow-pokes!" he laughed, teasing.
For his part, being the shortest one of the bunch and therefore having shorter legs, Luke was doing his best to catch up. Being a farm-kid, though, meant that he was used to hard work and doing a lot of running around, so at least he wasn't out of breath or anything.. That would've been embarrassing.
"What're those!" he gasped at the sight of the tigers. They didn't have anything remotely like them on Tatooine--but then again, there wasn't much on the desert-planet.