The Quadzilla Complex is a 3-exercise body-weight leg circuit run back-to-back in quick succession.
5 in-place lunges
5 jumping lunges
5 squat jumps
Do the lunges 5 times each leg, as each lunge counts as half a rep. For the in-place lunges it's important to step forward into the lunge, not step back, and touch your knee to the ground each rep.
For the jumping lunges, ensure the back knee touches the ground each rep, explosively hop up and switch your feet in the air, then drop down into the next effort. Control your descent–don't slam your knees.