An invitation to seize an opportunity with vigor.
Hey man, I'm not sure if I should pursue computer programming.
Bro, grab it and growl, grab it and growl.
A beastlier way of saying "dig in!" or "enjoy!"
Jon: Hey, Dave's back with the burgers!
Dave: Here ya go, grab on and growl!
When there isn't anything planned for dinner so everyone eats whatever they want for dinner. "Grab" what you want to eat and "Growl"/fight over it if there is a limited number of something and two people want it.
What's the plan for dinner tonight?
Grab and growl