You've always found the idea of a lamia kind of cute. Besides, it would be easier for the reptilian to become a lamia due to evolution. You place your finger on the reptile's head and store the genes it would need to eventually create a lamia.
You snap your fingers and a tree house apears in a nearby tree. You also shrink to a human's size after the snap. The tree looks like something you would find in the Amazon rainforest. Your tree house is a standard one, a box of wood nailed in between two branches. Underneath the floor of your shelter is a trapdoor: with a ladder underneath that. You ascend the ladder with your bloated stomach shaking side to side.
When you reach the inside of your structure, you take off your suit of armor. You watch as your stomach pops out and becomes three times as large as you. You massage your stomach as the people inside squirm heavily. You could talk to one of them, or you could wait for a lamia to appear.