I'm having trouble understanding your recommendation. Vagrants take ALL of their belongings with them, they have little where else to store any items they. Backpackers couldn't possibly take everything they own with them or they would by definition be Vagrants.
I think having a Vagrant as the mascot for Vagrant is the only obvious option.
Ok, my point is that both take their belogings with them. Backpackers take the stuff they need to travel around. Same as Vagrants, as you mentioned. But, to the market, having a Vagrant as a mascot might be seen in bad taste. Thus, to reduce the chance of rain over his parade, he could potentially just change mascots. That way, people who get easily offended by anything won't have an excuse to say anything. Plus, when this product gets more and more traction, people will question the mascot choice. That's why Frostred Flakes has Tony the Tiger, and not Bad Luck Johnny that lives under a bridge. Its all about perception. Though this is an issue some hacker don't get, because to them the world is black and white. Not saying it is you, of course. Just talking out loud.
Also, why the only obvious option?
Why couldn't it be a Puppy, Cat, Horse, Printer, Cloud, Keyboard, Fish, or anything else? Why the Vagrant? Its not obvious. For all the client know Vagrant might be an acronym or some made up tech name.
I think having a Vagrant as the mascot for Vagrant is the only obvious option.