I checked the quarantine sketchbook out from start to finish. It was fun. The sketches were very detailed and they were not just Hellboy universe or some unique monsters by mignola. Mignola made skeches of many characters in pop culture as well from Kermit the Frog to Flintstones and Mars Attack to Spider-Man Villains. I especially liked his Thundercats. I would really like to read a Mignola drawn Thundercats comics. I wish he drew Ninja Turtles as well. I would really like to see Mignola's take on Ninja Turtles. I would also like to see more DC Comics characters sketches... There were many Marvel Monsters and villains sketches, but there were only two robot Batman sketches from DC or something.
Here is the Index, it lists evey sketch in the Quarantine Sketchbook. The Quality of the picture is not very good though, sorry.