Phantom cats, also known as alien big cats (ABCs), are large felids which allegedly appear in regions outside their indigenous range. Sightings, tracks, and predation have been reported in a number of countries including Australia, Canada, China, Denmark, Finland, France, Germany, Ireland, India, Italy, Luxembourg, Netherlands, New Zealand, Spain, Switzerland, the United Kingdom, and the United States. When confirmed, they are typically explained as exotic pets or escapees from private zoos.

Sightings of exotic big cats in Australia began during the 19th century. It is generally thought that sightings may be attributed to escaped exotic circus animals such as Matthew St Leon's touring circus in the 1870s and large cats brought back as pets by soldiers. In one such example, in 1924, a puma and a jaguar both escaped from the Perry Brothers circus while traveling from St Arnaud, Victoria by train when their carriage's wall collapsed. The jaguar was captured after stunning itself, and the Puma later shot.

The New South Wales State Government reported in 2003 that "more likely than not" there were a number of exotic big cats living deep in the bushlands near Sydney.

Phantom cats reported in Australia include

In June of 2025, sightings of a large black cat or panther were reported in the eastern city of Shumen. Later, sightings of what was assumed to be the same animal were reported in the towns of Giurgiu and Năsturelu in Romania. Although no hard evidence has been documented, one hypothesis is that it escaped from captivity, perhaps from an illegal, private zoo owned by criminals, or migrated from Hungary or Serbia. Experts have suggested that evidence of tracks could be attributed to large dogs.

The blue, or Maltese, tiger, the former name taken from the common color terminology for domestic cats, is a purported color morph of the South China tiger, with sightings in Myanmar, China, and the Korean Peninsula. It is speculated that while the color morph may have theoretically existed, the severe historical bottlenecking of tiger populations makes it unlikely for the genotype to remain in extant populations.

In 1995, a big cat usually described as a lion (but sometimes as a lynx) was dubbed the "beast of Funen" by numerous eyewitnesses. There was an earlier big cat sighting from 1982 in southern Jutland.

A supposed lion moved around Ruokolahti near the Finnish-Russian border in June–August 1992. There were multiple sightings. Tracks were identified by a government biologist as a big feline not native to Finland. The biologist was given police powers to capture or shoot the lion by the Ministry of the Interior. Border guards participated in the hunt. The last reported sightings were in Russia and there were reports that the lion was seen by Finnish border guards and that lion tracks were found in the raked sand field used by Russian border guards to detect crossings. The lion was never captured and the incidents have never been explained. One possible explanation could have been a railway accident of a circus train in Russia, from which some animals escaped.