Halloween // How does one go about making realistic slime/gore/monster props?

So a couple years ago for Halloween I made a rotting corpse prop for my outdoor display kind of like this one: https://cutediyprojects.com/halloween/30-astounding-but-easy-diy-outdoor-halloween-decoration-ideas/attachment/decayed-corpse-halloween-prop/

You make it by melting plastic drop sheets onto a cheap plastic skeleton and then painting it.

I really had fun making it and ever since, I've wanted to challenge myself again with something similar, only I wanted to make it less "decay" based and more gore/slime based.

For example, I'll be watching a movie like "The Thing", pretty well known for its practical effects, and I'll see the spider with the human head or the dog kennel slime creature and think, "That's an actual thing that somebody made."

So I want to know how you make things like that. Like, can anyone point me towards any tutorials that show how to make a realistic creature or gore props? Anything slimy or oozing or bloody, haha.

I'm obviously a beginner so some relatively easy DIY stuff is ideal, but I still do have a curiosity about making things with latex and and doing casts and such. I may not be able to actually do anything too advanced at this point but I'd still love to see the process!

Basically I just want to create one really badass looking creature or prop for my Halloween display this year and wouldn't mind just making a fun hobby out of it over the summer!