Me and my brother were talking about the symbolism behind the location of the homunculi's tattoo's location (i.e. Greed's is on his hand because he wants to get a hold of everything, Gluttony's is on his tongue because he wants to eat everything, etc.) and after reading all of the Fullmetal Alchemist manga three times over, neither of us could remember the location of Pride's homunculus tattoo.
In the manga and Brotherhood, Pride does not have an Ouroboros tattoo. He instead has only a small circular mark on his true form's body.
Below is an image of said mark, but definitely contains spoilers for anyone not finished episode 37 of Brotherhood (and perhaps could be considered spoiler material for anyone who has finished episode 64).
On the FMA Wikia it states and from general knowledge on my part in the 2009 & Manga...
But in the 2003 Anime from my memory, is that...
Just pictures of what the Ouroborus looks like. On the left is in the Anime and on the right the Manga.