photos are a bit small, but looks like an Agave alright... Agave attenuata (foxtail Agave).

Picture in May 2012

Hi, thank you for the reply!
It does look like a Agave Attenuata, but the mother plant doesn't grow taller but grows side way...
What is the best way to take care of it? The leaves look narrow and dry now... :(

After I did some research of Agave Attenuata online, I think this is more like a Agave Desmettiana.

It is a very vigorous jade

Not a Jade....definitely not. It is a tropical Agave. I think (and I say think) that it is an Ag. attenuata. They have a tendency to grow sidewards when larger.

Did you catch this thread? It might be aa good one for you if you didn't

Here is a link that might be useful: Repotting a foxtail

Could be A. ellemetiana, which is a bit uncommon, or possibly a Beschorneria or Manfreda. Leaf seems very narrow for attenuata, which is not at all rare in southern California. Are you trying to grow that in the house? Depending on how far inland you are, some morning sun followed by afternoon shade would help it. Closer to the coast, more sun.

Agaves pup or don't pup depending on age, placement, climate, they don't have a set number of pups per year. Some offset only when young, some only before they are about to bloom, some never at all, some offset so much as to be a weed.

To wantonamara:
I just read the post, but, I've already got it repotted a year ago.

To hoovb:
It looks like the Manfreda but with no spots on it. I'm trying to have my friend take a picture of the mother plant, and will post it when I got it.

Something I didn't mentioned.

I live in So Cal, about 30 miles from the coast (LA county).
I got the baby plant in May 2012, kept the plant in shade, outdoor, only watered it when the plant looked dry. It didn't seem doing well, so I re-potted it in March 2013.

The original plan for re-potting was just add some perlite at the bottom of the pot to prevent root rot. But then I found out the roots were growing around and around inside the pot, so I decided to switch to an even larger pot 6.5"-dia about 1 gal pot(see in this picture).

After that, I tried to move it under the sun, but it didn't work. And then I'm here...

From reading the plant care for all the Agave family, some says water it but some don't, most of it says partial sun is fine. But I just don't see what went wrong that this plant just hasn't seem happy since I got it. Ahhhhh~

But if this might be a A.D., A.A. or A.E, some website says it needs medium water when it's not established. Should I just try water it a lot more and see what's going on? Will I kill it?

More Picture~

Doesn't look familiar to me.

I had an A. attenuata pup that looked just like that.

Why don't you ask your friend?

are those teeth I see on the sides?

Ok~ here is the picture of the mother plant. From this picturr, it looks like its an A.A. to me.
Also, it was planted by the landspcaper so my friend doesn't know the name.

It has some very fine teeth on the side.

Now that looks vaguely familiar, Agave 'Blue Flame', an hybrid that is especially common in SoCal.

when I finally noticed those teeth I thought, "I think I have a plant with teeth like that." I concur with the German, Blue Flame.

That's a good friend you have there. I don't like any of my friends that much to part with a Blue Flame pup. lol

OMG, thank you, GermanStar!! I think it is the Blue Flame!!

Now, I think, I'll try water it regularly and see if I can bring it to life ^_^

Thank you everyon for the help! I'll post some more pictures in a couple of months~

I've been giving it more water then before but kept it at the same place; it seems happy now :) Just wanna to follow up and let you guys know~