Pure, by default.

Islamic jurisprudence, fiqh, works from a small number of great maxims. One of them says that a thing is pure until there is evidence that it is impure; a sister maxim says that a thing is permitted until there is evidence that it is forbidden.

So the question for a tail is not “where does it say a tail is allowed?” It is “is there anything impure in it?” And that is a question about the material, which is a question we can answer.

Our fur is synthetic: made in a factory, from no animal at all. It never had blood, never had saliva, and was never alive. By the default, it is ṭāhir, pure.

The jurists take dogs seriously. A well-known hadith in Sahih Muslim says that a vessel a dog has licked is washed seven times, the first with earth. The four Sunni schools then disagree, at length and in detail, about what exactly in a dog is impure.

On every view, then, our fox tail is fine: it was never an animal of any kind, so no school’s rule about dogs can reach it. There is no pig anywhere in our catalog, and the shark is plush.

Cats come out of fiqh much better than dogs. A companion of the Prophet was so fond of a cat that he is known to history as Abu Hurayra, the father of the kitten. And in a hadith collected by Abu Dawud and al-Tirmidhi, the Prophet is reported to have said of a cat that drank from a vessel of water: she is not impure; she is one of those who go about among you.

Which makes our cat tail the one with the strongest precedent on this page, from the material up.

There is a famous hadith that silk and gold are forbidden to the men of the community and permitted to its women. It is the reason many Muslim men wear silver wedding rings.

Our fur is not silk. Our plug is stainless steel, never gold. Whatever else a man may need to ask his scholar about, he does not need to ask about the gold.

Prayer, ṣalāh, needs purity of body, clothing and place, and a valid wuḍūʾ, the washing before prayer. A pure material passes the first test. The second is where the schools are pedantic, and here it matters.

For the Ḥanafīs, Shāfiʿīs and Ḥanbalīs, anything that leaves either of the two passages breaks wuḍūʾ, even something unusual. For the Mālikīs, only the usual things do.

In practice: take the tail out first, then make wuḍūʾ, then pray. Not the other way round.

During the fast of Ramadan, the classical schools held that something entering the body through an opening can break the fast, and they discussed medical cases with great precision: drops, kohl, enemas. Later scholars, Ibn Taymiyya among them, disagreed about several of them, and modern fatwas still do.

The Ḥanafī texts are more exact still. Ibn ʿĀbidīn’s Radd al-Muḥtār distinguishes an object that disappears inside, which breaks the fast, from one whose end stays outside, which does not, because it never settles. A tail, by definition, stays outside. We still give the easy advice: after iftar.

Islam does not treat intimacy between spouses as a regrettable necessity. In a hadith in Sahih Muslim, the Prophet tells his companions that even in a man’s intimacy with his wife there is ṣadaqa, charity, and when they are surprised, explains why.

Which acts, and how, is a question the schools answer in detail and do not all answer alike. That part is for you, your spouse and the scholar you trust. The material, at least, is settled.