Just a revised version of this art work piece (http://www.furaffinity.net/view/32026546/) with a few further alterations.

Description from previous piece

Here is a Heathcliff fan art piece i did based upon my own interpretation of something that never actually happened in the show proper, namely that being Heathcliff meeting Riff Raff and Cleo so this head canon style piece shows how i would personally picture it happening. As in, he has already previously met and befriended them both at some other point in time and then brings Sonja along so they can to be properly introduced to her as well, i would like to think she'd also become good friends with them and especially Cleo who i'd reckon she'd more than likely bond with quite well and have as a gal pal, and as you can see they are just chatting it up and having a grand old time. This is how i would see it likely occurring if they actually did cross paths in the show.