Barrel cats, while terrestrial for the most part, have a close affinity to water. They're found across the Southern coastlines of both split halves of the Catland supercontinent, as some individual cats made the crossing across the narrow sea on rare occasion. They have done this because they can survive better for sustained periods of time in the water than other cats, and are out of the size range of smaller squid, so are less likely than other cats to be hunted by squid (or in recent times, especially large fish) before they get to the other side. They're heavy and tube-shaped, with shorter legs than other cat species compared to their body length, which helps them sustain momentum in the water. It does, however, make them slightly slower, making them more reliant on ambush when hunting terrestrial prey. Their broad, paddle-like paws spread silently on the dirt or sand, making them stealthy for their size. But most of their food comes washed up on the beach, or is hunted in the water.

Slinks are nemesis to the barrel cats, their opposite in most ways that matter. They are fast, long-legged and less reliant on stealth and ambush (except for populations that rely on wading to hunt fish and aquatic invertebrates in wetland habitats). Although not strictly social, the slink is capable of teamwork while the barrel cat will rarely cooperate with other barrel cats. Slinks, similar to pallis, may sometimes nip and harass competition out of an area or do the same to prey to burn through their stamina and exhaust them. There are many more slink species in East Catland than West Catland. Although Slinks migrated across the gap between East and West Catland when it was narrower, they never spread particularly far into West Catland, meeting competition and predation from other cat species more suited for their respective habitats and local prey.

This solitary slink thought it could steal a kitten from an unattended nesting spot, but the kitten mewed as soon as it was grabbed. Almost instantly the rustling of vegetation and rapidly approaching thrumping of paws across the sand could be heard. In it's fright the slink fumbled with the kitten and dropped it before kicking up dust in it's hasty escape with the barrel cat in hot pursuit. Although not much longer and certainly shorter than the slink, the barrel cat is more muscular, has a greater bite force and has more weight to throw around. It would kill the slink if it managed to catch it, but the slink is faster and manages to escape.