by Bogdan Bendziukov on WordPress.org
This plugin adds the ability to set a mask to Gutenberg's image block or via shortcode [wp-image-mask].

Select your image (or add a new one from Gutenberg blocks).
Select a custom mask for your Gutenberg image’s block or add a masked image anywhere via shortcode [wp-image-mask].
Shortcode attributes:
src – URL of the image;mask – URL of the mask;fit – how the mask should fit into the image. cover, contain (default contain);alt – alt text for the image.