Starting off with a two for one, it's pretty obvious that both Neyla and Rajan are meant to be mainland or bengal tigers (Panthera tigris tigris). They were originally conceived by the developers as father and daughter afterall.

I think pretty much everyone knows what tigers are and what they're all about (solitary apex predators, live in Asia) so I'll spare you the details, and share some lesser known facts about them instead.

Most relevant to the topic at hand, the bengal tiger was long considered a separate subspecies from the siberian, chinese and malayan populations, but recent genetical analysis suggests that they all belong to the same subspecies, and are now collectively referred to as the mainland tiger. The only other extant subspecies being the Sunda Islands or sumatran tiger.

Contrary to what Bentley would have you believe, tigers do NOT have an aversion to water. In fact they are some of the best swimmers among big cats, with the population in the Sundarbans being known to swim between islands in the delta in search of prey.

And contrary to popular belief, there are NOT more tigers in captivity in the US than there are tigers in the wild. @why-animals-do-the-thing has a very well researched series examining the data regarding captive tigers in the US which you can find here.

Sidenote: As a kid I thought that Neyla was supposed to be just a normal (purple) tabby cat. It wasn't until I got older and heard Dimitri's office recordings that I realized she was supposed to be a tiger.

Speaking of Dimitri, he is obviously an iguana of some kind. There are no wild iguanas in France, but i guess his family could have migrated there. Some fans have identified him as a marine iguana (Amblyrhynchus cristatus), but his pointed skull and impressive dewlap beard suggests to me that he belongs to the genus of true iguanas (yes, taxonomy is confusing).

There are two recognised species of the Iguana genus; the green iguana (Iguana iguana) and the lesser antilliean iguana (Iguana delicatissima). I couldn't decide which one fit Dimitri better so you're getting another two for one. Both species grow to be up to six feet long, with males being larger than females. They are herbivorous, and feed on a wide variety of leaves, flowers, seeds and fruits. Both species live in forest and swamp areas, and are very capable swimmers and climbers. In addition to having well-developed vision, iguanas also possess a so-called parietal eye placed at the top of their skull, which allows them to detect ultra-violet light.

The green iguana is by far the most widespread of the two species, being found throughout most of Central America and northern South America, along with invasive populations in Florida and the Carribean. It is also one of the most popular lizards in the pet trade, even though it can be notoriously demanding and stroppy.

By contrast, the lesser antillean iguana is critically endangered, being only found on the archipelago of Lesser Antilles. Here it faces threats from invasive species, such as feral dogs and cats, but its greatest threat is, ironically enough, its invasive cousin the green iguana. The two species compete over resources, and can even interbreed, creating hybrids which further limit the native population.

The Contessa is most likely a black widow spider of the genus Latrodectus, seeing as she's often associated with an hourglass symbol which several members of the genus famously display on their abdomen. There are way too many Latrodectus species to count, so I'm just gonna assume that she is a southern black widow (Latrodectus mactans) which is basically the type species for the genus.

The southern black widow is the most common Latrodectus species in North America, being found throughout the southeastern United States along with Mexico and the Dominican Republic. Like other spiders it largely preys on insects, but sometimes also preys on other spiders, including its fellow species.

Black widows are infamous for their venom, which causes a condition called Latrodectism. This venom is rarely fatal in humans, with fatalities usually being those already of poor health, but it is extremely painful, causing symptons like nausea, vomiting, and muscle pain. These symptoms can sometimes last for weeks.

Black widows are of course also known for practicing sexual cannibalism, where the larger female will consume the male after mating, hence the "widow" name. This is not guaranteed however, as the female may spare the male if she isn't hungry. The females are generally the deadlier of the species though, as they are not only larger, but also have more potent venom (and a longer lifespan). All very fitting for a character who likely poisoned her husband.

As for Jean Bison, I actually like to think that he is a wisent or european bison (Bison bonasus). Part of that is his design. While his head is definitely big, it isn't quite as ridicoulously large as that of an american bison (Bison bison). More importantly however, I think it makes more sense for a european colonizer trying to industrialize the wild north, as opposed to a native american animal.

The european bison is distinquished from its american relative by being generally smaller and lankier in frame, but it is still a large and powerful animal. Adult bulls stand 6 feet tall at the shoulder (taller than the american bison) and can weigh up to 900 kg, making them the largest land animal in all of Europe.

The species has historically had a range covering most of northern Europe, but overhunting and habitat loss drove them to extinction in the wild in the early 20th century. Less than 60 animals remained in zoos worldwide, but thanks to wildlife rehabilitation efforts the species is slowly but steadily recovering. Today they are found in scattered populations across Europe, mostly in the east.

All in all, quite an ironic fit for a villain who's goal involves destroying the natural environment.

And finally we have Arpeggio. I had a hard time choosing between two particular species for him; the yellow faced parrot (Alipiopsitta xanthops), and the golden parakeet (Guaruba guarouba). Thanks to @arpeggio-the-parrot for coining me in on that last one. The yellow-faced has a more appropriate plumage, but the parakeet has a more prominent beak, much like Arpeggio. This combined with features we'll discuss later makes me conclude that he must be a golden parakeet. I do also kinda like the idea of him being a flightless kakapo, but I digress.

The golden parakeet or golden conure is only found in the Amazon Basin of northern Brazil. The species is endangered in the wild due to deforestation and the pet trade. It has a diet largely consisting of fruits and seeds, particularly corn. This is a highly social species, with up to 10 individuals roosting in the same tree hole. Different females will lay their eggs in a single nest, and when the chicks hatch they are raised communally.