Board Thread:Theories and Speculation/@comment-27590087-20160111050921/@comment-9782468-20160111061400

Orochimaru did a bunch of genetic experiments on himself that made him more snake-like. It's not a nature release.

For future reference, direct questions like this should be directed at the Naruto Answers Wiki. I know you're new so it's not too much of a problem. Make sure you read the forum policy if you have any questions. Feel free to also drop a question on my talkpage.