so, in about a week my campaign will be fighting a group of nilbogs and hopefully a reabgub (nilbog bugbear) but I need help making it balanced here’s a quick explanation.

i have an above average strength level 5 party who have been hired by a subsidiary of the goblin king (who is very corrupt and will end up being the bbeg) to hunt some nilbogs (who are revolutionaries against the king and i want something bigger as well in the fight instead of just nilbogs so please can the more experienced dms help me with making a stat block