Cub

A cub is a preadolescent mammal, usually ursine or feline. The young of certain species may have more specific titles; for example, young canines may be called pups; young foxes, kits; etc.

Legal issues regarding cub media
Regarding "cub porn", as of 2010, there are no worldwide laws that explicitly refer to sexual depictions of minors other than humans, and there is no known case of cub pornography being used to prosecute anyone in a court of law. However, there are laws in many countries which could be used to prosecute people if the issue was argued in court. These can include obscenity, bestiality and child pornography laws which rely on some interpretation based on opinion.

There are, however laws covering cartoon pornography depicting minors, and Australia has implemented laws strictly prohibiting any depiction of child pornography "even one which departs from recognizable human forms in some significant respects"; the UK has enacted a similar law. These laws have extended to pornography of real people who are over the age of consent but appear to not be. People have been convicted numerous times for possessing non-anthro cartoon pornography, although some of these cases have been overturned on appeal.

Cub and furry
Within furry fandom, the term cub may be used to refer from roleplaying grown up and adolescent human furries (e.g. Babyfurs, most often fursuited than not), to all imaginary, created characters under the age of majority, from babies to tweens.

This has particular relevance due to the prevalence of furry adult media in the fandom, which is often restricted using this criterion, but, because such drawings do not depict a physical person, it is impossible to determine their age, therefore some legal systems depend on analysis based on the psychical attributes of normal human development (breasts, pubic hair, muscle tone, and size) for age estimation. This can be impractical for fantasy creatures such as taurs, griffons, and dragons, which display few human age-related traits.

Fur Affinity
On November 5, 2006, due to a belief that cub-related adult artwork did not violate US law, Fur Affinity began to allow pornographic cub submissions, with the requirement of proper tagging. This caveat was to go with a then-promised future feature of the site which would allow users to block tags for content they do not wish to see. (This tag-blocking feature has never been implemented.) Prior to this, such artwork was prohibited by the TOS.

In November 2010, Fur Affinity again banned adult cub artwork from its website, after payment processor AlertPay cancelled its donations account. According to site owner Dragoneer, the only choice was to ban such artwork or lose the site. The move fuelled growth at Inkbunny, which had opened shortly before with a tag-blocking system allowing such material to co-exist with those not wishing to see it.

Inkbunny
Inkbunny was founded in part by individuals involved with Softpaw Magazine. The site allows adult cub art and written stories, and lead admin GreenReaper has stated a belief such works are legally protected due to not depicting human characters. As a corollary to this, artwork, stories, and thumbnails depicting human characters (or "essentially human" ones, such as nekos) in adult situations, regardless of age, is prohibited.

Weasyl
Weasyl has banned cub pornography since its founding. Specifically, the site prohibits art and story submissions containing "Minors in sexual/mature situations" and those depicted with "unacceptable nudity". For the purposes of the rule, "minor" and "underage" characters include those drawn with child- or infant-like proportions, with allowances for "chibi" stylization.

SoFurry
Prior to May 31, 2018, SoFurry prohibited "realistic depictions of human underage characters", but citing unspecified changes to how relevant laws are interpreted, banned all visual cub artwork that was rated above their "All Ages" rating. Users were given a single day to remove artwork that violated the new policy, after which moderators would automatically remove such art, without penalty for submissions uploaded before the change. They also allowed a grace period lasting until October 31, 2018, during which users who uploaded artwork violating the new policy would be informed of the change. After the grace period, their normal policy of policy violations will apply.

Cub Central
Cub Central was a website that hosted cub-related art and stories, including that which was adult in nature. Largely eclipsed by Fur Affinity in 2007, the site closed down permanently in 2015 when the original owner passed away.

Discord
In 2018, the VoIP service Discord amended its Terms of Service to ban drawn pornography of underaged characters.

Government censorship of furry sites
In 2008, a list of web addresses to be blocked in Australia was spread via Wikileaks; it included several images of cub porn hosted on e621. The spread of HTTPS, which conceals the URL being accessed, has led to both Fur Affinity and Inkbunny being blacklisted by Russia.