Hellboy Library Edition 4. Fun stories, drawn by a variety of artists. The one that I did not enjoy as much is the one with the ghoul reciting poetry. The old-style English poems were a bit hard to follow for a non-native speaker (especially a very tired one )
Overall, the stories did not do much to push the main narrative forward but I did really enjoy the world building.
In my reading order, BPRD Plague of Frogs Volume 1 is next. I already read through what I think are the first two TPBs worth of material with various stories which were not all written by Mignola. They were very enjoyable nonetheless. Interestingly, I have read somewhere that it took them a while to get the team dynamics right but I had the idea that the characters were great right from the start. There was even a story in there by some guy named Geoff Johns. You may have heard of him
I've now reached the first issue of the Plague of Frogs proper and will hopefully start on it tonight.