Summoning: Toad Mouth Bind

Unlike the usual practice of summoning an entire creature, the user instead summons only the oesophagus of a giant toad from. The oesophagus is summoned around a target; if this is done inside a cave or some other structure, it's possible the target will not even notice. The walls of the oesophagus are sticky and pliable, making it difficult for opponents to keep their footing and, therefore, fight as normal. The oesophagus is ordinarily inescapable, and over time it will contract around and digest its victims.

Jiraiya can control the oesophagus, causing it to expand, contract, or grow in whatever direction he wishes. When first used, Jiraiya claims that no one has ever escaped from this technique. Itachi Uchiha and Kisame Hoshigaki manage to escape when Itachi burns through the oesophagus using Amaterasu. This surprises Jiraiya, as the oesophagus is fire-resistant due to the toad's ability to breathe fire.

Trivia

 * is a Japanese name for a pouch or wallet, especially one closed with a metal clasp and used for small change. Naruto's own wallet is a reference to this word as well.
 * In various video games, parts of the oesophagus also spew fire.