The Chronicles of Sheldon Mayer's Sugar & Spike
Sugar & Spike #10 
Reprints: None [yet]
Dedication: Roberta Disano (age 10), NJ
The kids are taken to the beach, which they enjoy, and they aren't at all tired when put down for a nap so they sneak away. When they find a pile of sand with feet sticking out if it, they come to the logical conclusion that the sand from their sandbox walked there, and begin to worry about how its going to get home. Meanwhile, their parents finally notice they're missing, and their fathers show what courage really is.
Interesting lettering error, the man in the sand has babytalk style balloons for his speech, instead of grown-up talk.
Characters: Sugar, Spike, all four parents, unnamed man in sand and other beach-going extras
Damage: minimal, that hat filled with sand might never be the same
Sugar's treatment of Spike: he's grabbed rather harshly and thrown into the face of the man in the sand
"Did you know sand had feet?"