Kedamono sends this in: “For the life of me I don’t get the joke made by the alien, Odom. And I can see the word balloons.”
The construction is curious. Is the yellow character (the editor isn’t fully familiar with this strip) supposed to be seeing/hearing some of the word balloons but not others? Is the joke just going over their head?
Comics I Don't Understand 
Over their heads, eh?
And yes, Boody, the yellow dragon, is a regular on Mythtickle, but no, they don’t often do fourth-wall gags.
The dragon was confused at the “space humor” line because it heard, “We plan it.” The alien then realizes that the dragon missed the pun because it can’t see the words written out.