Shoe: It must be a naptop.

See what the wizard-repairman bird-guy did there? He changed the first letter of "laptop" from an "l" to an "n" to create the word "naptop" instead. He did this because Cosmo always falls asleep when uses this particular laptop. This is the reason Cosmo called wizard-repairman bird-guy. Obviously.

And so I can only conclude that this comic is hilarious not because of the word play (which, after all, is not hilarious), but rather because Cosmo is a moron and the wizard-repairman bird-guy is about to beat him to death with a wrench.