The Legend, the Myth, the Great Nothing Special from the fabulous Age of Aulde - Phil Foglio's voyage into the land of porn tasteful nudity-plus(*).
//(*)with humour

To place the points straight: this is the original run of the series, which held for ten issues. Not eleven. Compare and contrast last page blurbs on the Vol 1 and the Vol 6 of the XXXenophile Collection.
Content-wise, original ten issues of XXXenophile were reprinted later as first five tomes of Collection in question: same stories, different ordering - plus scant new additions as a "mandatory voluntary" thing the artist included, if my memory serves me right.
Volume six of the Collection contains only the brand new story "Heart of Stone"; and plans were laid to continue series in that form - tomes - specifically, making the sole exception for the Issue №11 of XXXenophile proper, in which new materials created for the Collection were reprinted in old form of newsprint comic. In the afterword, Foglio specifically talks about it being the last issue in such format, and all the further stories set to be released as a part of future tomes in XXXenophile Collection.
We all know how that ended.

But I digress.

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Artist
* Flagship - https://www.girlgeniusonline.com/
* Patreon - https://www.patreon.com/girlgenius

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Issues and volumes:

** Original run
* Issue 01 (demon girl; female clone selfcest; robot girl)
* Issue 02 (superhero nonsense; a whole grove of dryads, I suppose; there is a robot joke here somewhere...)
* Issue 03 (mmf; panther on woman; advertisement fairy; lesbians IN SPACE!!)
*> Issue 04 (group yuri session; shaming of the Unclean One; math; third vanilla in a row)
* Issue 05 (non-humanoid alien; mile-high club; elfess; ffm with clones; check, mate)
* Issue 06 (centaur/human switcheroo; La Llorona, after a fashion; lesbians IN SPORT!!; harem of male clones)
* Issue 07 (a naiad; genuine honest-to-gods phone sex (talk about well-aged concepts... Jesus wept, I'm old); non-humanoid alien from Vol5's better part in mtf threesome; dog with human brain)
* Issue 08 (ye gawd of aulde and foul witchery; that one robot from Metropolis; new employee orientation; either exhibitionism, or hidden sex - depending on perspective; the bed, and the Thing under it)
* Issue 09 (dragon layer; Tales of the Velvet Fist; ye aulde curse(s)+; assorted myctical shenanigans)
* Issue 10 (of gods and ceremonies; Joe Schmoe's usual day at work; r63 with SCIENCE!!; classic first contact problems)
* Issue 11 (later addition)

** XXXenophile Collection
* Volume 1
* Volume 2
* Volume 3
* Volume 4
* Volume 5
* Volume 6