Generally, bugbears are bigger, stronger, stealthy goblin type monsters. Delvers have noticed that these monsters come in separate size categories. The smallest are the 'runts' or 'squits', about the size of a goblin, about four feet tall with a similar build. Larger, stronger bugbears are known as 'jacks'. These creatures are about the size and strength of a hobgoblin. Fully developed bugbears are over seven feet tall and can get larger. They are significantly more difficult to kill. Some can reach the size of a hill giant and are correspondingly tough.
Some sages have speculated that the runts represent young bugbears and that jacks are females of the species. Recent research has indicated, however, that runts are actually made from goblins using some sort of despicable process known only to bugbears. What is involved in this horrible transformation can only be guessed at, however. As to gender specifics, the heavy fur of the bugbear makes it difficult to tell if bugbears are gendered at all. Certainly it is not a subject that civilized minds inquire about.
All bugbears are naturally stealthy, surprising opponents 50% of the time, under normal conditions. This includes runts who use this stealth, along with their small size, to ambush and kill hapless travelers or to steal valuable items from human abodes or other monster's lairs. Runts appear to desire the recognition of their ilk and frequently take their ill-gotten gains back to the larger bugbears. It is thought that this allows them to develop into jacks in some way.
While runts prefer to fight using ambush tactics, jacks are not averse to a straight-on fight. They are rude, violent, and cruel, prone to tormenting weaker creatures. Jacks frequently capture smaller humanoids to use as servants and slaves. Goblins in particular are much sought after, to turn into new bugbears and replenish the strength of the band. They themselves are bullied by the strongest bugbears.
The largest bugbears are very strong and can throw larger hand held weapons such as maces, hammers, morning stars, and battle axes as though they were throwing axes, up to 4”, anything under 2” being treated as medium range. They frequently carry more than one weapon, so they can throw the first and blood the enemy before closing for melee.
Bugbears are reasonably intelligent, and can see well in daylight. Like goblins, they can see even in full darkness up to 60 feet. They will eat food and consume drink (especially alcohol, which they enjoy greatly) but do not actually require sustenance as long as they are in their natural surroundings (gloomy dungeons or forsaken wilderness).
Bugbears prefer to wear odd loose fitting clothing of they type favorite by foppish nobles. Thus ruffs, hose, doublets, capes, and bonnets or caps are frequently sported by these creatures. Their servants are also forced to wear similar types of clothing. Usually they alternate two primary or secondary colors and striped, spotted, checked, or plaid patterns. Bugbears of different bands wear different colors and are usually very aggressive towards each other.
Like goblins and other fairy-tale creatures, bugbears do not have awe of the divine. Quite the opposite in fact. They delight in stealing items precious to those who have true faith, so they can defile, hide, or destroy them. Bugbears do not appear to cast spells, although they do use items which seem to require arcane magical talent to employ properly.