A proper cactus dance can be described as standing as awkwardly straight as possible, bending the elbows at 90 degrees (much like a large cactus), and facing knees in the same direction, also heavily bent. You want to retain the position as closely as possible while flailing the arms and shifting the hips so the knees sway back and forth.
While executing these moves, just remember nobody brings it like you do. This dance successfully ends when the dancer is hit over the head with a heavy blunt object.
b) "Beware, I know the cactus dance."
c) Zach: "Darren, I really don't think its working."
Darren: "Just give me a another hour, we'll be having beers with Nosferatu in no time."