Gents,
I've always been intrigued by the 'Sewer Rats'(1) ever since reading the various snippets about them scattered through MT. It's a shame they were left out of GT:Humaniti. Then again, considering how bad that product was maybe is wasn't a shame after all.
There's an illo of them in one of the MT core books, shows a rather squat hairy fellow wearing a harness of some sort. MT also mentions them supposedly having a 'sector-sized' STL empire when contacted by the Vilani (I believe GT:ISW shrunk that size somewhat.)
The T4 article presented them as bio-engineers of a sort, something to do with the huge trees they lived in/around/beside/within. Each of their STL generation ships reportedly had a whopping huge sequoia or something growing down the middle.
Of course, my real interest in the Suerrat has to do with their sector of origin; Ilelish. That's the sector which rebelled against the Imperium in the 400s and was home sweet home for Dulinor too. (He's not Suerrat.) When the Imperium put down the revolt in the 400s, it evacuated Ilelish - the Suerrat homeworld - and reportedly 'scrubbed the equatorial regions free of life'.
Interesting, no?
Have fun,
Bill
1 - During the first TML New York Real Space meeting several years back, we scared nearby several pub patrons by discussing, among other things, the 'proper' way to pronounce Suerrat.