Once upon a time, back when the Earth wasn't a cesspool of garbage and toxic gases run by cockroaches, the only species that could survive such a noxious environment, cats would keep humans as pets. It started back in Ancient Egypt mostly, where the people viewed them as being regal and majestic, which of course inflated the already large feline ego enough to think they were right. Over time, however, cats became fond of humans enough to try and help them, like by teaching them things; one such lesson was hunting, which would involve bringing humans kills like mice or birds. Some people came to expect this of cats, who just kept trying to teach humans, and around it went for centuries.
"Hey Cat man, why aren't you more⦠well, cat like?" Lister asked over his beer and crispies, the felinoid lapping his milk and crispies with a nice shiny silver spoon.
"What would you know about Cats?"
"I know a lot man, had a few over the years. Mostly toms, but hey, cats all the same."
"Okay, what sort of things did those cats do that I don't?"
"Didn't use all the smegging hot water for starters, cats back on Earth usually hated water."
"Sounds fishy. What else?"
"Nagged me and my mates for attention, getting us all to pet them and scratch behind their ears."
"Touch my clothes or ruin my hair and you'll get scratched," he hissed.
"They'd bring me dead things, like mice and birdies, probably thinking I just didn't know how to hunt or somethin', I dunno."
The Cat stared at Lister a long moment, then sniffed slightly and showed off his fangs, as if in challenge. "Birdies huh? Guess they knew you monkeys couldn't do anything right."
Almost a week later, as Rimmer was coming back from his run, he found Lister and Cat standing at the table looking down at a badminton birdie, one stunned and the other expectant.
"What's going on here?" His question was met with silence.
"They've been standing like that for awhile now Arn, I'm starting to worry." Holly's face popped on the screen.
Rimmer huffed and sat (hovered really) on his bunk, waiting for either Lister or Cat to do or say something. Eventually, the felinoid swiped at the man and growled, "So, here's your birdie, stupid monkey, now where's my treat?"
"I meant a birdie that flies, well flew, like a raven or somethin', not this!"
"It's still a birdie," Cat mentioned smugly.
"Yes Listy, it's definitely a birdie, maybe the Cat thinks you need exercise," Rimmer piped in, laughing.
"Oh ha-ha Rimmah, stuff it." Lister went over to the fridge and got a can of tuna out. "Here's a treat, now smeg off."
Cat took the can, clutching it to his chest, and grinned toothily. "Don't have to tell me twice buddy," and he yeowled his way out, twirling merrily.
"That was interesting, that was," Holly nodded. "Why'd he bring you a birdie Dave?"
"Nothing, nevermind, forget this ever happened." But Lister picked up the proffered prize and stuffed it in his pocket, later putting it with his most precious little mementoes, smiling at the fact that Cat did care, even if he rarely showed it.
Years later, on a rebuilt Red Dwarf, Kristine Kochanski found a small box, burnt and beaten, in Lister's cabinet and she couldn't resist looking in it. There were a few pictures of this universe's version of her, a few bits and bobbles she knew her Dave had, and a badminton shuttlecock. She understood the rest of box, it all seemed like the Dave she'd come to know in this universe, but the shuttlecock was not something she could figure out. When Lister found her with it, he freaked out and grabbed it from her, clutching it to his chest and rushing off to hide it somewhere new, his anger more at her handling his birdie than anything else.
