Grims are a sentient species of bipedal felines from Earth West 1,617,525, descended from the big cats of their Earth, They also walk mostly on two legs though they are much smaller than humans, rarely going over a meter in height on their hind legs. Up until recently the cats showed little to no interest in learning to communicate with humans. With the Grims being less cooperative than their canine counterparts, the lessons of the Beagles fresh in their minds, and due to severe allergies from the head scientist, the Long Earth pioneer crew mostly left the cats to themselves. Because of this little is known about how Grimalkin society works but based on limited observation most agree it's similar to packs of suburban feral cats on Datum Earth. In the last few years the Grimalkin have found themselves as a sort of tourist destination for misguided cat loving humans across the Long Earths determined to make the trek to a land of soft little kitties. Unfortunately these tourists, disappointed to find themselves surrounded by large feral cats (and a strong smell of cat urine), have, in heedless attempts to domesticate the locals, introduced catnip to Earth West 1,617,525. While this has created a devastating catnip problem it has also had the useful effect of encouraging the cats – particularly the younger cats to learn to communicate with and on occasion to work with humans.