Type: A huge huge huge dog. And no, in case you haven't figured it out yet...he's not a wolf. I've heard people say that he's a wolf before- I think that threw me off more than the transformation itself. Got me all confused because I thought they were talking about Kouga. Imagine my confusion when they were saying that the wolf saved Rin and I was all thinking..."But it was Kouga who indirectly killed Rin with his wolves..what the hell are these people talking about??" XD

Appearance: In his dog form, he retains the prussian blue crescent moon on his forehead while the stripes on his cheeks changes slightly to merge and "wrap" around the edge of his jaw. His eyes becomes completely red and his ears naturally turns into flappy dog ears. :) His fur is white just like his hair though there are areas that look a bit gray. Several parts of his fur are quite unruly, making them look like white flames- he has a patch of it around each of his paws which is a nice touch as it makes his legs appear more balanced in terms of size.

Taking a closer look at his dog form, you'll notice that there's actually also an extra piece of the "white flames" fur that wraps around his right shoulder and then around his body. This is quite interesting, especially since he also has the infamous boa-look-alike piece of fur around his right shoulder whilst in his human form. This then lends theory to the idea that these two pieces of fur are actually the same one. If this is correct, then that "mysterious furry object" isn't a tail, a boa, nor armpit hair but instead a part of his dog form that stays behind after his transformation. Whether there's a specific purpose in this piece of fur or not isn't known either. Overall, I'd say he looks pretty intimidating in his true form. :)

Size: Gigantic. :D After he transforms, everyone else is basically only about the size of his paws. You can see a picture of the comparison down below on the right hand side. Even though he's already very big, he's actually probably still only a puppy. His late father's dog form was much much larger- as was shown on some memory flashback scenes and his massive tomb/bones. This then further confirms the theory that Sesshoumaru is not yet a fully grown youkai.

Method of Transformation: Sesshoumaru is able to transform at his own free will as well as stay in control of his true youkai form and mind. The first and only time that he's ever fully transformed seemed to come at ease- it didn't look as though he needed any special preparation, etc. I said "fully transformed" just now because there are times in the later episodes where he was beginning the process of transformation but then stopped himself for one reason or the other. From what I've noticed, the times that he wants to transform usually comes when he's angry or having difficulty in beating the opponent with his human form- an exception being the battle between his true form and Inuyasha. In that case, he had apparently transformed for the sake of testing how powerful Inuyasha would be with the Tessaiga.

The Transformation: The process of his transformation basically looks like an evolution chart. He starts off with his eyes still white but his pupils shrinking in size. Then slowly, the marks on his cheeks thickens until their edges become jagged. The color also changes a bit while his whole eye goes red with his pupils turning blue/purple. After a brief transition, his eyes become larger than normal while the pupils basically turns into two dots in a pool of red. On some shots, they actually look like slits instead. On the first picture above and the pictures below, you can sort of get an idea of what I'm describing.

At this point, Sesshoumaru actually looks like Inuyasha during the "youkai blood possession" state, except Inuyasha stays that way while Sesshoumaru transforms much further. His nose eventually elongates into that of a dog which makes him look like a human with a dog's nose and mouth- quite an image to take, I thought. Anyhow, during this whole process- he seems to emit some kind of energy (I'm assumming it's Sesshoumaru's powerful jaki) and a strong wind begins blowing harder and harder until it looks like he's surrounded by a twister- and that's when he completes his transformation into the big dog.