How can I make a second Avatar on my account

[Rhumple]

Is it possible or do I need a new account

[Rhumple]

Is it possible or do I need a new account

[Rolig Loon]

That depends on what you mean.  When you open an account, it has a unique username and UUID.  There can be only one with those labels.  You can open a second account -- actually, up to 5 accounts -- and each will have a unique name and UUID.  We call those alts.  You can log in with both accounts at once, if you like, and control your alts separately.  So, if that's what you mean by having a second avatar, you need a second account.

Your avatar in world, however, can change shape, skin, and gender as much as you like.  You can certainly save many different appearances as outfits and then switch from one to another any time you want.  Your username and UUID don't change, but you don't look like the same person.  If that's what you mean by having a second avatar, go right ahead. You don't need a new acccount to create as many avatars as you want.

[MartinRJ Fayray]

In addition to what Rolig said, you can also change your display name, see: http://community.secondlife.com/t5/English-Knowledge-Base/Usernames-and-display-names/ta-p/700173