Wildcard Processor (Mikey)

If you've seen prompts online littered with things like __hairstyle__ or __pose__ and wondered what those double-underscore tags actually do, this is the node that resolves them. Wildcard Processor takes a block of text, finds every __something__ reference, swaps each one for a random line pulled from a matching text file, and hands you back a plain string ready for a CLIP Text Encode node.

How the wildcard system works

This is file-based wildcards, not the inline {option1|option2|option3} syntax some other tools use (that variant exists too, elsewhere in the ComfyUI ecosystem, but it's a different mechanism entirely - don't confuse the two). Mikey Nodes' version reads from .txt files living in ComfyUI/wildcards/, one option per line. Write __hairstyle__ in your prompt and it grabs a random line from wildcards/hairstyle.txt.

The syntax has real depth once you need it, straight from the README:

• __word__ - pick one random line from word.txt.
• 2$$__word__ - pick 2 lines instead of 1.
• __word|term__ - only consider lines in the file that contain "term."
• __!word__ - lock the selection to the seed, so re-running with the same seed always picks the same line (useful for reproducing a specific result).
• __+word__ / __-word__ - step the selection one line forward or back from the seed-derived pick.
• __*word__ - force a different random line than the seed would normally pick.

The inputs and output

Just two inputs: prompt (a multiline text box - this is where your wildcard-laden prompt goes) and seed (an integer that drives which lines get picked, including all the offset/lock behavior above). One output: a resolved STRING with every wildcard swapped out for real text, ready to feed a CLIP Text Encode node or any other prompt-consuming node downstream.

Pair the seed here with the same seed you're using on your KSampler if you want the wildcard selection to move in lockstep with your generation seed - that's the whole point of the __!word__ lock syntax.

Installing it

It's part of the full Mikey Nodes pack - search "Mikey Nodes" in ComfyUI Manager and install, or cd ComfyUI/custom_nodes && git clone https://github.com/bash-j/mikey_nodes then restart. The one thing to actually set up yourself: create the wildcards folder in your ComfyUI root if it doesn't exist, and drop in .txt files named after whatever tags you want to use. There's no bundled wildcard library - you're the one writing (or downloading community sets for) the actual word lists.

Where this trips people up

• Empty output for a wildcard tag. If __hairstyle__ resolves to nothing, the most common cause is a missing or misnamed file - it has to be hairstyle.txt exactly, sitting directly in ComfyUI/wildcards/, not a subfolder unless your workflow accounts for that.
• "Random" that isn't actually random between runs. If you're getting the same wildcard pick every time and don't want that, check whether your seed is fixed upstream (common when you've locked a KSampler seed for A/B testing prompts) - the wildcard pick follows the same seed by design.
• Confusing this with the <style:name> syntax. Mikey Nodes' separate Prompt With Style node uses a different tag format entirely for its built-in style library - that's not what Wildcard Processor reads. Keep the two systems mentally separate; they solve different problems and use different files.