Dripping Ooze
Great for your Halloween decorations.. I use it for a Leaking Radioactive Barrel. Easy to scale up/down. Easy to bend with a heat gun for a rounded object.
For glow under black light I use: "NOVAMAKER 3D Printer Filament - Yellow 1.75mm PETG " available on Amazon. Note that it's their PETG not PLA that reacts under blacklight.
I print with 15% infill usually rectalinear (Gyroid Prints but a bit more sloppy). 15 % is enough that it comes out clean and sturdy, but can also be bent by heat gun.
This is based on Madjack's " Blood Run:
https://www.thingiverse.com/thing:1201131