Berserker Orcs are female Orcs, known for their fast movement speed, immunity to slow debuffs, and heavy melee damage.
The mini-boss variant for Berserker Orc is Gnash the Flame Lance, a larger Berserker Orc who wields a flaming blade that can set your heroes or defenses on fire, dealing extra damage over time.
Berserker Orcs are notorious for running past barricades and other distractions, quickly reaching and killing any objectives. As a result, they can easily catch unaware players off guard and killing the objectives before players have time to react. This can be prevented by sealing up lanes with barricades, so that enemies are unable to simply walk around them. If a barricade goes down, act quickly to rebuild the barricade before Berserker Orcs leak through.
Due to their fast movement speed and heavy damage, they are also very effective at destroying barricades. Traps and nodes capable of stunning are commonly used to control and counter them - just because they're immune to slow effects doesn't mean they can't be stunned. Make sure that there are defences to quickly kill Berserker Orcs that do reach the barricades. The Shielding Guard and Sharpened Spikes shards are often used as well to keep the barricades alive until the defences can kill them.
When dealing with Berserker Orcs head-on with a melee-oriented hero, be wary of their heavy melee damage. Keep a distance whenever possible, and back up when they swing.