Board Thread:Naruto Discussions/@comment-1276314-20151221233227/@comment-26369387-20151222000942

Actually, the seal was 'snake'. Compare 'snake' and 'boar' upside down and you'll see which one it is.

Anyway, the name of technique seems to be 秘術・襟巻蜥蜴(エリマキトカゲ), Hijutsu: Erimakitokage(Secret Technique: Frill-Necked Lizard).

As for why it isn't here... Shrugs