This is a juvenile. Basilisks can run really fast on their hind legs, and with their spread-out back feet they can even run across water, a habit that has earned them the nickname "Jesus Christ lizards".

The large crest is a mark of an adult male.

This species is officially known as the Brown Basilisk, but the Common Basilisk is also sometimes called Brown Basilisks, to distinguish them from the beautiful Basiliscus plumifrons, or Green Basilisk.

This is yet another non-native species that's now running wild in South Florida, along with the Cuban Brown Anole, the Puerto Rican Crested Anole, the Green Iguana, the Tropical House Gecko, the Brahminy Blind Snake, and many others.

Along the edge of the Red Road canal, a large population of brown basilisks thrives. These three are all large adults. The last one is particular old and grizzled (but still remarkably fast).

A warm December day brought out the non-native Florida basilisks again in large numbers. The first four here are in order of increasing age and size, from a tiny hatchling (cute!) to a full-sized adult (what a tail!). The fifth and last photo shows a subadult basilisk snacking on a Brown Anole, another non-native Floridian lizard. These basilisks are extremely fast and quite shy, so it's always a challenge to notice them from far enough away to get a photo before they speed off into the bushes or across the water.