I am planning to add some deamons to my 3mm fantasy Beastmen so have been collecting various options. When it comes to large demonic creates (since demons do not have to be 6 foot tall), in addition to what Malika posted, I am planning to use these:
http://titan-forge.com/daemonic-kingdom ... -ignorance and I am planning to use 6mm Microworld ones also:
https://www.microworldgames.com/collect ... asy/DemonsHowever, if you want 3mm tall models, the best I can think of is various swarm bases, such as these from CP Models:
https://cpmodels.co.uk/product-category ... re-swarms/ Paint them in lurid colours and you have some fairly demonic stuff. There are also the Reaper Bones swarms:
https://www.reapermini.com/Miniatures/SwarmThere are lots of sources for potential inspiration from 10mm Warmaster demon armies, such as these:
http://www.forum.specialist-arms.com/in ... opic=988.0 (incidently, there was an even more impressive 10mm demon army on the internet, I thought on specialist armies, which looked quite similar to these but even more impressive (they might be a later version of this army). If anyone know what I am talking about and has links to pictures I would be most grateful as I was planning to use it as inspiration).