Looks:
Jaken has green skin, big buggy eyes, and a beak-like mouth. He's usually wearing a brown outfit, with a little hat on his head, and a staff in his hands. He doesn't even come up to Sesshoumaru's knees (although he comes kind of close to them), but often proves himself to be helpful to the Taiyoukai.
Weapons:
That staff he carries around is called the Staff of Heads, or the Staff of Skulls. It's used to locate the tomb of Inuyasha's father, and the man's head on the staff is capable of blowing fire out at enemies. Sesshoumaru also leaves him with Ah-Un, so I suppose Jaken is also protected by the two-headed dragon.
Up side:
When it comes to loyalty, this little demon is right up there with the dogs. I mean, Sesshoumaru has sliced him in half with Tenseiga, kicked him around, stepped on him, hit him, etc., and he keeps coming back!! He can also be pretty helpful in figuring things out, since it was him who suggested to Lord Sesshoumaru that Inuyasha might know about Tetsusaiga's location. He also helps protect Rin, since he knows Sesshoumaru would kill him if Rin got hurt.
Down side:
Annoying little toad, who always seems to get on everyone's nerves. He doesn't know when to shut up, and tends to be over-confident in Sesshoumaru. He's always bad-mouthing humans and half-demons, which means he's not very nice to Rin, either.
Overall:
Jaken is a loyal but annoying person to have around. No wonder Sesshoumaru feels the need to hit him occasionally. But, maybe he can end up being nicer to Rin later on in the series...
