When you have taken damage in the past turn, you can gain a +1 to your strength ability score till your next turn(to a maximum of +1). You can do this twice per short rest.

Whenever you land a melee critical hit, you can re-roll all damage dice of 1 or 2.

Select one skill, tool or weapon to be proficient in. At level 10, you can pick another.

Like orcs, minor wounds against you seem to have little effect.

When you take unmodified damage less than your <your level/4) round up,you ignore it. You still are counted as having taken damage. You can do this once per turn.

You gain advantage on intimidation checks.

Half-Orcs are able to stay at the brink of death when they endure crippling damage. 

When you drop below 0 hit points, you come back at 1 hitpoint instead. You can only do so once after taking a long rest.