Bristleback

Rigwarl the Bristleback is a melee Strength hero famous for his array of synergistic spells with low mana cost and cooldown. He is able to slow his enemies down and reduce their armor with Viscous Nasal Goo, then hit them with a barrage of Quill Sprays, making him an effective chaser when ganking enemies. His low strength gain makes him less tanky than most strength heroes, but he becomes substantially more durable when he turns around due to his passive Bristleback, which reduces damage taken from behind. In the right hands, Bristleback is a powerful ganker in the early stages of the game, and a powerful semi-carry in the later stages depending on how much farm he gets.

Tips

 * Use your passive skill Bristleback to your advantage; anticipate enemy attacks and turn your back on them, so that you can reduce as much damage as you can.
 * An early skill point on this skill during the laning phase can help you stay in the lane a while longer, especially if you are having trouble against auto-attacks.
 * Even if your enemies can easily defend against you with a Magic Wand, you can still heavily damage them with Warpath; as long as you're stacking your spells against them, the bonus damage will do its job.
 * Viscous Nasal Goo is an extremely useful cripple, provided that you keep casting it against your target, as it slows their movement speed for 32/44/56/68%. The cripple's duration is up to you, since you can continuously cast it to refresh the duration, and its cooldown is only 1.5 seconds.
 * This skill is very effective when combined with Warlock's Fatal Bonds, as the damage inflicted on the crippled target from other bound creeps or heroes is applied to the armor reduced hero at said reduced value. This makes the Bristleback/Warlock lane combination very potent, even into the late game. When combined with area of effect items and attacks, a lot of damage can be dealt very quickly.
 * Bristleback's mana woes can easily be remedied by a Sage's Mask or a Ring of Basilius, since his skills have extremely low mana costs.
 * One of Bristleback's main weaknesses is his lack of disables, meaning he cannot silence or interrupt an enemy from casting spells. You can either rely on your teammates for disables, or create an item of your own, so long as it benefits him in some way (a good example would be a Scythe of Vyse, since it gives him good mana regeneration for his skills, and a devastating hex disable).

Trivia

 * In DotA, Bristleback's hero model was a quillboar, having a much more boar-like appearance. His loss of boar-like features in Dota 2 was likely made to distinguish him from the quillboar race in the Warcraft universe. As well, his hero title shares the name of a large quillboar tribe in World of Warcraft.
 * Bristleback has the highest intelligence gain per level of any hero whose main stat isn't intelligence.