[catthumb] to embed a thumbnail image for a category.
[catthumb id="CategoryID" link="true"] will find the most recent post in the specified Category with a featured image and return the thumbnail for that image. If link="true" is specified, the image will link to the category specified.
You can optionally search custom post types with the
post_type attribute, and specify the thumbnail size with the
size attribute. IE
[catthumb id="CategoryID" link="true" post_type="restaurants" size="full"]
The plugin will only search featured images, not attached images. It will not look for images embedded in the post itself, or other attached images. If a category does not have any posts with featured images, this plugin will not return a thumbnail image, even if the category has posts with attached images.