Spanky is Phil’s Slab Boy sidekick. He plays a key role in the humour of the play.
He is quick-witted and plays well off of Phil. Like Phil he is rebellious to a degree, and cheerfully mocks:
Is Waldorf Bathroom your uncle or what?
I mean what doll's going to take a guy seriously in that outfit and with a head like that, Heck?
Fairies been putting cement in them again?
It's a bloody operating table you want to be on, Jack. That face...yeugh
While Phil's sense of humour begins to lead to more open anger and bullying, Spanky's taunting of others remains comparably jovial throughout the play. His behaviour is held in check by a sense of conscience and concern for the others involved.
After Hector goes missing, Spanky is genuinely concerned (so long as it doesn't interrupt his lunch) and pulls Phil up about what he has done:
He'll get bloody frostbite, ya swine. How could you do that to him?
And while he is compassionate and understanding about Phil's family situation, he defends Alan from Phil's verbal attack:
Leave him alone, Phil...he doesn't know what you are talking about.
Spanky has dreams of leaving the slab room but is more grounded than Phil. His ambition is smaller than Phil's. He hopes to make his way into the design room one day. And he seems willing to bide his time until his opportunity arrives. He reels off the time others spent to get promoted before suggesting the deciding factors:
...who knows? Depends if they take to your features...how many desks are free...how the boss if feeling...what the Berlin situation's like.
This suggests Spanky does not take personal responsibility for his ambitions. He seems to see promotion as something that happens to you, based on random factors beyond your control. For all Spanky's rebellious talk, there is much that is very conventional about him. His views on progress and status can be very traditional.
On hearing of Phil’s dismissal, he responds to Phil sarcastically addressing him as ‘slab boy’ with ‘at least I still am one’. By the close of the play Spanky’s situation is completely unchanged, he is not going to the dance with Lucille, he has not been fired or promoted; he carries on grinding, accepting of his role but still waiting for his situation to change:
Wait till I get my desk...just wait!