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Ancestor: Zootoca vivipara (Common Lizard) 

Size: 20 cm including tail.

Dietary Needs: Invertebrates, ranging in size from tiny gnats to beetles and butterflies. The latter they sometimes  fail to capture if the insect is particularly large. They can press their short tongue up to a leaf or other smooth surface that is within reach if they see a gnat sitting on it, which is a fairly effortless way to catch a very low reward snack. In  other lizard species, gnats are only large enough for the hatchlings and newborns to consider worth eating, but in Grass-tail Lizards the adults will notice and eat them too. They also eat insect larvae, such as mealworms and caterpillars, and they eat small earthworms they find on the ground or lost and confused in the grass. Most lizards eat invertebrate prey in one bite or whole, but Grass-tail Lizards are so small they usually take several bites out of larger invertebrates.

Life Cycle: Males have blue tails in the "green" season, when the lizards are exposed to green light from the flora in their environment. These tails are an indicator of good health - the more vibrant, the more well-fed the male is and the less chance he will get sick. He needs to stand out because the females are bigger, stronger and the more selective sex when picking a mate. They don't want to stand out because they will be carrying their unborn offspring as soon as possible. They have more to risk if they die, whereas the male only has to get mating over with to carry on his lineage.

Males who lose their tails to a larger predatory lizard such as  the Grass-stalker Lizard become unattractive to the females as a result, but the trade-off is that without that blue tail he will be better camouflaged until it grows back. His movement in the grass will be more cumbersome however.

There  is now only one morph of female. The low clutch size, higher survival rate female died out in the ancestor populations for this species. They are an r-selected species with high offspring variation. The low fitness offspring take some of the heat from predators off the high fitness offspring.

Other: They are not particularly fast runners, though they are still capable of a short scramble to get out of immediate harm's way. Instead they rely on camouflage and concealment within the grass. Their long tail also helps spread out their weight and give them more anchorage so they can climb across the top of the grass without falling through as easily, a means they might employ when avoiding danger closer to the ground.

To remain camouflaged even in the dry season, being green relies on green light entering the eyes. If the lizard can't perceive enough green light in it's environment, a hormone signal begins a process that breaks down structural blue in the scales. The green colouration fully disappears next time the skin is shed, leaving them a golden colour with light brown spotting.