I'm new to the Morrowind CS and am trying to make a custom creature npc trader. I think I have most of it figured out, but for some reason in game I can never talk to the creature. I've tried cloning Creeper and the mudcrab and changing the creature type and animation, but it still doesn't work. Halp please!

You need to give the creature a unique greeting in order to talk to it. Creatures require an assigned greeting, or dialogue will not open for them. Go to the greetings list, and make a new greeting while dialogue is unfiltered, set it to the creature, and you're done!