Riddle me this:
My prefix can rip and tear, pointy or curled,
Where ours mainly grip unless werewolves exist.
My suffix is greener in one perfect world.
Some yellow is seen, where some gardens consist.
My infix has rules unlike the underworld.
It governs like schools; do not break or resist!
And now change the vowel to between the IP.
Or throw in the towel, but that works if you see.
What could I be?
The answer is just $5$ letters long, and the title owns a clue.