This is the first book of 'Bloom County' from Berkeley Breathed. To me, it seems to be more of an experiment in which characters and ideas that were going to continue. There's quite a bit of various hedge hogs (or a Porcupine, I think) a bear with Cutter John and some other assorted animals and people chars.
After BB created the The Academia Waltz, you can see some characters that were 'ported' over the Bloom County - Steve Dallas and cutter John (who was originally called Saigon John) to name two.
Some of the well-known characters are not here in Loose Tails ( Portnoy the Gopher, Oliver W. Jones, Lola, etc.). Steve Dallas' char. is pretty much here, as well as Milo, and Cutter John. Bill is introduced, and the rest are being developed or decided on. After "Loose Tails", the next collection of Comics, "Toons for Our Times", seems to have the line-up of chars set and going.
Unless you're a collector, or very hardcore Berk. B, I might not recommend it. If you really like Opus and Bill, Binkley's closet, Oliver and his inventions, etc. Then I would start at about "Toons For Our Times", and stop at "Happy Trails". The Char's are more stable within these collections.
BTW, "Outland" by BB, uses some of the same char's, but it's changed. Not the same feel, but the insanity is more. Opus is one of the few that continue on the same as well as Oliver. Bill the Cat seems changed a bit, some new additions, and some appearances/char's that are brought back later as the strip continues.