One of the most notorious crime lords in the galaxy, Jabba the Hutt has a lot of power an influence over the actions of others. With his vast wealth and resources, he can afford to put out large bounties on anyone that crosses him. He can also afford to pay for the best bodyguards around. Other characters who live on the fringes of society will do what they can to impress Jabba in the hopes of joining in with his criminal organization, and hopefully stay on his good graces. That's the sort of stuff Jabba also does in Imperial Assault.
Jabba's not one to get his own hands dirty. He'd much rather just get someone else to do it for him. He has four different actions he can do that make some other character do something. It might be as simple as just having someone else attack for him. Considering some of the nasty other attacks that are out there, having an extra shot from one of your key figures can certainly turn the tide of battle. He's also rather sturdy, having 10 health of his own. Though don't expect him to be dodging out of the way of too many shots headed his direction. You'll definitely want to keep him out of the line of fire.