Actually, the Frackles get a page to themselves, but only JG, Green Frackle, and Blue Frackle are mentioned. But, hey, it's better than nothing.
Really? I keep looking at the content listing page on Muppet Wiki and Frackles is not listed. I guess it might be an oversight.
And by Green Frackle, it is Gloat, right, and not the one that's also known as Green Scoff (that characters design was labeled "Green Frackle", but was actually called Green Scoff in a Muppet Show Annual) or the green one that looks like a green version of Boppity (the Blue Frackle)?
I'm sort of surprised Mo Frackle isn't included. He's been used in a lot of productions in the last few years, after being absent for a long time after his initial appearances on Family Feud in 2001.
I decided to count the pages and characters. It looks like there are less than 150 pages (but I don't know what all is two or more pages, and as you said there are "filler" pages which I guess aren't listed on the wiki page). Then I counted all characters, including pairings, and I counted either 202 or 204 characters (I should have said this right away when I started posting). That includes five Clodhoppers, eight Muppaphone (even though there's usually only six, but their first appearance had eight), five members of the Muppets Tonight band, eight members of Geri and the Atrics (including Geri's replacement and the false teeth), three Mutations, five Moopets (assuming Foozie is included), two Snowths, four Fazoobs, three Leprechauns, three Hobos, and I even counted both Robin and Tiny Tim separately (I probably shouldn't have, but the book does include him in the Cratchet Children page), but there are groups I counted only once, like Chickens, Penguins, Lobsters, and Muppet Food.
Looking at the list, I see now that Muppy is actually included. I didn't see it before.
I'm surprised '80s Robot is not in this. '80s Robot does appear in Muppets Most Wanted, which the book apparently gives a lot of focus to when it comes to characters who appear in that movie (if there's a second edition maybe it should focus less on MMW). It does include the Hobos, after all.