Why the hell is the dotted line the Family Troll - Part Four as straight as an arrow? It goes through solid objects, which a FC dotted line never does.
I'm fairly certain the joke is supposed to be "they'll never think to come this way, but, ha ha, they've left a thick dotted line behind them!"
Even if it's not, this is a big old FAIL. The whole point of the Family Circus dotted line strips is that the lines meander as the children meander, all over the neighborhood, into houses, shops, trees, etc. The whole point of the FC dotted line joke is that children are hard to keep up with because they will go for whatever attracts their eye.
This seems to be pure laziness. If you're going to do an homage or a parody, don't neglect to include the most iconic aspect of the thing you are referencing.
Other than that, I'm enjoying the Foxtrot element.
Update: I realized after I posted this, and the first commenter pointed out: the whole joke might be that the line is straight, and the FC kids wouldn't be able to find them because it is straight. Fair enough, I retract my opinion that it's big FAIL.
However, I think there's potential for a much better joke there, a clearer one. A decoy dotted line leading away from Skull and whatshisname would have been cleverer, implying that the dotted lines, which don't really exist in the world of the comic (but only to the reader), are actually real.