Entity: Desert Rat

Source Advanced Player's Guide pg. 21 ^2.0

You are native to arid plains and likely grew up traveling the roads. You have a leaner build than other ratfolk, with longer limbs and short fur. If you have both hands free, you can increase your Speed to 30 feet as you run on all fours. In addition, environmental heat effects are one step less extreme for you, and you can go 10 times as long as normal before you are affected by starvation or thirst. However, unless you wear protective gear or take shelter, environmental cold effects are one step more extreme for you.