Taxonomy's terms with last/random post thumbnail

So far I’ve been using “wp_list_categories” in order to display a list of my taxonomies’s terms. For each line the result would be something like:

<li><a>Term name</a>(number of articles)</li>

Now I would like to be able to achieve something more eyecatching than a simple text-based unsorted list: more in detail, I would love to see a list of terms, and for each line the term’s name, term’s description and if possible a thumbnail from either the last or from a random post inside that taxonomy term.

I’ve tried to search this argoument both on Google and Wp’s forums but I didn’t manage to find anything similar to that: given my lack of PHP knowledge, I’d like to ask if what I asked is actually possibile, if it’s already been made, if you could point me to a post/discussion/tutorial and/or help me somehow achieve this result.

Thanks in advance.