Gnolls, Bandits, Murlocs are the most common creeps found upon the game as a whole.
Kobolds, Forest Trolls & Ogres I'd rate as second and yet in my remake the obvious trolls and ogres are more fitting to be Horde Units, whether Old or New.
I updated my whole world editor to the point I updated all abilities, polished them, organized them, categorized them, & distributed them upon all units to make each creep challenging, unique & even added smart AI where they use all abilities at their disposal.
Then I thought; Goblins & updated them too. They summon Pocket Factories to summon Clockwerk Robots to explode their enemies, to attack you and on the field the goblins repair them.
They summon mortars that function like wards that bombard you from afar.
When a Mole Machine appears out of nowhere, goblins emerge from it to attack you.
Goblins are engineers. They are tinkerers. To see them you see destruction & damnation.
They are businessmen for the highest bidder as well & the East Venture Trading Company is hired to hunt down Thrall, & they appear with Hovercrafts on the Darkspear Islands.
Rizz Boomer, your legacy lives on, my goblin friend. The goblins shall rule again!
When they tell you it's a bad idea, no it's not if you do it right. Rock on!