Baal, one of many gods and goddesses that the Israelites "struggled" with.
God Uses His Own Failure to Set Up the Israelites (Judges, Chapter 3) - Just finished Chapter 3, and it was nothing more than a repeat of Chapter 2. If we remember Chapter 2, the Israelite's God fails to drive out all the inhabitants of the area, and instead chooses to let the Israelites dwell among the people and have them be tempted by their gods. And then, when people DO get tempted, God (aka Yahweh) gets pissed.
So, in Chapter 3 people start worshiping various gods, in particular Baalim (or Baal) and this prompts more anger from the Lordy. God even strengthens the neighboring Moabites to go against Israel, because God is pissed that the Israelites fell for His own trick and started worshiping other gods!!! It gets so bad for the Israelites that they actually wind up in the service of the Moabite king.
And so now, with their own god literally against them, the Israelites begin to weep. Finally, crazy ol' Yahweh starts to feel sorry for them and brings them "a messenger". This "messenger" is actually just an assassin - a very flashy, action hero type of assassin named Ehub.
He goes to the Moabite's King Eglon, who apparently is very fat, and drops one of those action hero one-liners. "I have a message for you - from God."
With that, Ehub quickly unsheaths a dagger from its hiding place on his thigh, and then stabs the king so deep into Eglon's fat - to the hilt - that Ehub is unable to retrieve the knife.
After that, it's just a repeat of previous books and chapters. The Israelites basically annihilate (for now) the Moabites and kill about 10,000 of them!
Finally, the chapter ends on an unrelated point. Some other hotshot Israelite named Shamgar apparently kills 600 Philistines with an ox goad. An ox goad is basically a cattle prod, a long stick with a point at the end. Presumably, he used it as a spear. But still, SIX HUNDRED!?! Spartans, beware.