the reason i doubt you made that is
1. its an obvious advertisment for another forum but doesnt link to anything.
2. you claim youve never made a sig before, and your first choice is and animated sig, not to mention a fairly decent flow especially for you saying its your first
3. the quality/style for all the sigs in the animation are completely different, meaning it wouldve taken quite a while just to make the sig portion. (first is just a render on a bg, second is a slightly faded render over a bg, third has some smudging and some effects done to the render, fourth just looks like a stock is taking up the full space, and last one is similar to the first except with a bit of the render erased.)
the only reason im digging into this is that as a GFXer myself, i highly dislike it when people post sigs, claiming that they made, when they didnt.