Q: What is Leg Day?
A: It's like any other day, but with legs. Specifically, it's a day where you do a lot of squats, deadlifts, and other exercises that make your legs hate you.
Q: Why should I do leg day?
A: You should do leg day because, honestly, who needs functional mobility when you have the option to waddle like an angry duck to the fridge in the middle of the night?
See Leg Day Exercise List ( warning: not for the faint of heart) Leg Day Do's and Don'ts (or else your legs will hate you)