I'm not a big feederism person but I did have an idea for a feeder/weight gain deltarune thing where it's the festival they've been talking about since the beginning and there's like a sort of carnival booth where you can pay to feed Catty, and you geta prize if you max out the scale she's on. You could do a cute thing where the foods people give her are themed to their character, like Noelle brings her fruit cake and Toriel gives her a buttspie. It ends with a joke where Sans shows up at the end and is like "Sorry I'm late to the festival guys. Whoa what's this." And then he tosses a coin to Catty's dad (who is running the booth) and tosses a singular water sausage dog into her mouth causing the scale's needle to move barely a centimeter to the highest number and the Sans wins the grand prize despite having been at the festival for all of 30 seconds. Everyone kills him.