Boise Ed sends:
and wonders, “I know Hagar often thrives on anachronistic stuff, but geez! Eddie having a modern pillow in camp is bad enough, but how would Hagar convince those two deer/elk/moose/reindeer to hold still for that, all night?”
I also have to ask what Rocky is doing down there on the bottom right–is one of those meese Bullwinkle?! In any case, where’s the joke?
Comics I Don't Understand 
Part of the joke is the inclusion of Rocky the Flying Squirrel in the corner.
This is a shout-out to both Dave Whammond (who puts a squirrel in the corner of his comics) and Jay Ward.
No joke involving moose would be complete without a link to Utah Phillips’ “Moose Turd Pie”. https://www.youtube.com/watch?v=trQW-1TnjSY
It’s Rocky ground, not just rocky ground.
Dvandom has a good one there, although it seems awfully subtle for this strip. I still wonder how Hagar got the Cervidae couple to stand still all night.
By the look of the moose on the right, he got them to stand still for it with drugs.