The second collection. Where the art is all the recognizable form. And things get introduced.
The guard dog appeared last time, but this time he takes form as the chained dog of the strip. Shtinky Pudding appears in a Christmas tale. Shnelly appears, or at least her ears -- she's only seen in the window as Mooch makes his first efforts to woo her. (And then gets over her.) For the first time, Mooch decides that this hibernation trick of the bear's is pretty cool and investigates. And we actually get a lead in to their annual summer vacation: Milly and Frank invite Ozzie to share their vacation beach home. Which introduces our favorite foul-mouthed crab, Crabby.
Other stories sequences, other stand-alones as well.