If you're looking for a tool to create pixel art images with AI, there are a few standouts. Pixelfy is a great option, with lots of pixel art styles for fantasy RPG characters and pixel portraits, a prompt builder, grid size controls and the ability to upload reference images. It's good for creative pros and game developers who want a lot of control.
Another good option is Picture it, an open-source AI art editor based on stable diffusion models. It's got fine-tuning image generation, guided drawing and inpainting abilities. It's geared for digital artists, designers and hobbyists, with a 4-step process to get the images you want and contributions from the community to keep the service fresh.
If you want a more general-purpose AI art generation tool, OpenArt offers a variety of AI drawing tools and editing abilities. You can create your own styles and models, and it's got boundary-free AI drawing and advanced editing abilities. Pricing levels range from free to professional-level credits, so you can use it on a shoestring or with a bigger creative budget.