Koba originally hails from the Western Frontier and is a hired gun on the streets of Scarabae. While he maintains skills in Stealth and special attacks such as Sneak Attacks, he also has a reputation for using proximity bombs (with a crystaline proximity bombs) or a wand attuned explosive (say the word into the wand and the bomb goes off). Criminal lords who hire Goblins aren't looking for a quiet war, they are looking for a series of bangs.
Malakara or 'Mala' is a Nightblade (a sorcerous-rogue) who is known as a 'city-clutch' - a Kobold that was born in the city, rather than in the mountains or morass in the area. Mala's specialty is a combination of stealth and frost magic. She loves the sensation of draining heat from her unfortunate victims. Criminals who hire her include Magister Syndicates or a gang boss that wants to build a reputation for delving in the arcane.
Pondabor is Minotaur muscle for hire with a knack of collecting debts from giantkin and large humanoids that live in the city. It's all to easy for a Minotaur to prey on Men, Gnomes, and Dwarves- but it takes a certain kind of braggadocio like Pondabor to tax Ogres, Orcs, and Minotaur. Pondabor also hires himself as a bodyguard. His best feature, besides being a Minotaur, is that he is good about staying bought to his patron.