A group of three Carnal Snakes guard the way forward on the 228th floor of Tartarus, within the Adamah Block. They block all ailments. After the Shadows are beaten, the Judgement Social Link will increase to Rank 5. Carnal Snake later reappears as a normal enemy in floors 237 to 261. Carnal Snake reappears later in the second and third section of Judecca within the Abyss of Time.
The Snakes are specialized for Fire and Darkness skills, but tend to to neutralize any immunities on your allies and clear any buffs or debuffs before attacking. They resist all magic except Ice and are neutral to physical skills. For an easy time against these bosses, field Koromaru and Junpei, setting them to Full Assault, and keep Aigis around as a buff-setter on Heal/Support. Akihiko is also viable as a debuffer. This setup will get the Snakes to waste a lot of turns on Fire Break, Dekaja and Dekunda while you dish out damage.
In Golden, Carnal Snake appears in Paradises 1 through 4. It gains a resistance to Wind. In battle, it acts similar to its Persona 4 appearance, but will try to enrage the party through Crazy Chain instead of poisoning them. It may also drop Meteorite for trade at Shiroku Pub. Selling eight Scorching Scales is enough to unlock the Adoracion in the shop.