Not everyone skilled in transfiguration can be an animagi. An Animagus form represents the person, just like a Patronus does.<br/><br/><div class="quoteheader"><div class="topslice_quote">Quote</div></div><blockquote class="bbc_standard_quote">Animagi can only take on the form of <strong>one</strong> specific animal. </blockquote><div class="quotefooter"><div class="botslice_quote"></div></div><br/>Source: Animagus (http://harrypotter.wikia.com/wiki/Animagus#Acquiring_the_skill).<br/><br/>There is a whole section on that page about Transfiguration vs. Animagus transformation. So technically, they are not the same thing. Though I would assume that those good at Transfiguration would be able to learn the ability a little easier since they would have a grasp on the idea of how to change one thing into another.