One of the Head Hunter's attacks is similar to a reward you get after a ToonTask, which is a small head.
The size of a Head Hunter's head is about the size of a Cupcake.
Head Hunter's Weakness is the Grand Piano, because it's over their "Head"!
On the trading card, the Head Hunter seems to be measuring a Toon's head.
One of the phrases a Head Hunter uses when he uses his signature move "Head Shrink" is "I shrink, therefore I am" which is a play on words of a Socrates quote: "I think, therefore I am."
Another one of them is "Honey, I shrunk the Toon," which is a play on words of the Disney live-action movie, Honey, I Shrunk the Kids. The only other cog to use this quote is the Downsizer. Coincidentally, they are both Bossbots.
Name of origin
In business terms, a Head Hunter is someone who is looking to give jobs.