We've seen the large band of coatis on both of our trips to Riu Tequila, in 2009 they were hanging out near the pool and near some of the rooms near the pool waiting for someone to take pity on them and give them a snack. They seem to come out near sundown and don't appear to be particularly frightened of the large international group of sun worshippers that were busy snapping pictures of them, perhaps they knew just how well fed we all were by the resort!
Coatis are a member of the raccoon family and are about 1-2 feet long with their tail being almost as long as their bodies. They have long snouts and their facial markings are similar to raccoons. They weigh between 6 and 18 lbs., about the same size as a domestic cat.
While strolling the grounds of our resort we saw an odd animal cross our paths, they looked sort of like large rats with a very small tail but they sat up on their hind legs like a squirrel when they were eating. They resort had a informational sign in German saying that they were agutis which I believe are agouti in English.
Agouti are about 16-25" long, weigh from 2 to 9 pounds. They are rodents with coarse black or brown hair, active during the day although we did see them in the early evening at the entrance to our resort. We also saw several of them in the garden area during the day and they seemed pretty harmless
If you look closely at the ground or in trees, you most assuredly will see lizards and iguanas near Playa del Carmen. We saw a lot at our resort, the Viva Maya, there was a small garden area where several of them spent their day sunning themselves. You could get pretty close to them to take pictures.