Spawning creatures in the mod toolkit

Hi all, hopefully this is the right place to ask this. I've started dipping my toes into creating mods using the mod toolkit, and for the current mod I'm messing around with I need a way to spawn a humanoid creature in the gameplay window for testing purposes. I know how to spawn items, or an enemy wolf, but I'm looking for a way to spawn an arbitrary creature. Is this possible? I've been looking at guides but all the ones I can find just mention the wolf. I found a video of someone just dragging a character from the root templates window into the level, but that doesn't work for me. I feel like I'm missing something super obvious.