This is something I simply don't need to see. It's a personal preference.
With maybe a handful exceptions, I've never been a fan of the Expanded Star Wars Universe. What do I need to know about the Rancor? They're big, mean monsters of awesome. One lived under Jabba's palace and ate things like defiant dancers and unlucky Gamorrean Guards. It had an emotional fat, bald caretaker and was eventually killed by Luke Skywalker... or a heavy door, if you want to get technical. That's all I need to know.
But if you want to know more, here's some [useless] info about the RANCOR found on Wookieepedia (the Star Wars wiki):
...They have been used for many things...[including] a source of food. Rancors were also the source of the delicacy (or at least an edible meal) known as 'raw rancor-beast liver'.
...While it is known that rancors did care for their young—usually born two at a time—they did not suckle and hatched from eggs like those of a reptile. The 3 meter tall hatchlings rode the mother, one dorsal, one ventral, until reaching maturity, though despite this nurturing nature, it was not entirely unheard of for a mother to eat her young.
...Rancors had a symbiotic relationship with Gibbit birds , and avian species that would clean their teeth, an action that provided the birds with food and the Rancors with a form of "dental hygiene."
...The word rancor (in American English) or rancour (in Commonwealth English) means "a feeling of deep and bitter anger and ill-will; hatred; malice."