Scratch

You will have to make another sprite designed however you want it. Then use this script.

Appearing Object
<when green flag clicked>
<hide>
<wait until><( <timer> <=> 100 )>
<go to[ other object

I'm afraid not    . If you want to pester the Scratch team about features like this, pester them via the link in my sig.

fg123 wrote:

Do you mean cloning? This feature is not yet implemented in scratch. Though various copies have made a block like that though. 

True, it is possible, but not in presentation mode, yet.
@Simple games
To do this you have to create all the needed sprites at the begining, then you have them show and hide, move around the screen and whatever you want, when you want them to.

Phi_Lho wrote:

Note: if your clones are static (eg. in a Game of Life, where items appear or disappear, but don't move), you can use stamp to copy an image of a sprite, and another blank stamp to erase it.
If they must move (eg. lot of bullets), it seems to be harder, indeed.

Bullets are easy, just make a set ammount of bullets, depending on the gun, 10s a good amount, you have a variable called Bullet_place, and you have it cycle through it, 1 → 10 and then reset at 1, and it broadcasts 'fire bullet' so you then have on each bullet, when it recives that broad cast it checks to see if its number is up, then if it is, it executes the firing stuff etc. and it loops round again.