READ ALL OF THIS!! Animate a transformation from the previous character to you! You must use the "Morph" custom block. The frameamount input is the number of frames your morphing animation has. The delay input is the wait between frames. The name input is your name. Make your animations SMOOTH, not choppy, Transitioning from the previous character to yours. You MUST not make animations choppy, slow or off looking. A common issue most people do is make the previous character look similar to yours, but then just snap to yours, Make sure the animation ends well, and looks like it doesn't snap, as well as the beginning.
Credit to Alzter! I just added my character! Hope he/she doesn't care that I added my own text...
