Your classic 'street-kid-come-good' routine, with bottle violence!
I deliberately tried to depict the most stereotypical image of 'life on the streets': graffiti, fires in 44 gallon drums, stray cats, etc...
Panel 4 is a tribute to 'The Simpsons', as Mull's combatant uses 'a board with a nail in it'.
I wanted Big Fella to be the ultimate life coach. For some reason, I picture him as Maori or Samoan. Maybe because of his tatts, which you'll notice are very similar to Mull's.
TRIVIA: These Origin episodes are in the order that each member joined the band. So Mad Dog and Beardo were the founders, then the others joined in the same order.
In the second-last panel, Mull is playing 'Suck My Kiss' by Red Hot Chili Peppers (and yes, it must be a 'magic singlet' for it to fit both Big Fella and Mull so snugly).
Finally, this was the first Origin episode to end positively. Mad Dog's ends mysteriously, Beardo's is comical but shows him having to start all over again, and Smiley is just depressed. I wanted to focus on the positive, as you will see I sort of do with the next one, too...