Where did the KKK get its bizarre titles for its hierarchy, such as “Imperial Wizard,” “Grand Goblin,” “King Kleagle,” and “Cyclops”?
The Reconstruction Klan emerged out of the minstrel tradition. It was a theatrical, racial performance, with the moral being follow the racial dogma of the Confederate South or great harm will come to you.
This is especially present when we look at the origins of the Klan. In Pulaski, Tennessee, the processor Klan organization was “The Midnight Rangers.” (Rangers being something akin to highway men of the south, roaming armed men of questionable legal status.) Here is an early photograph of them. These proto-Klansmen did not brandish the musket, but armed themselves with a different kind of weapon that showed their early roots in the minstrel or local folk tradition, musical instruments. In order to understand the Klan, one must understand the theatrics of the minstrel tradition.
The minstrel tradition was well established in the south before the Civil War. The Reconstruction Klan was always in line with local customs, and fed off these costumes in order to create the juggernaut of hate that it became–nothing develops out of nothing. It was a theater trope, that often allowed for stories to be told. Primarily, these stories were those that one must adhere to the racial dogma of the day. Just as these stories often had pranks at their base, the Reconstruction Klan viewed what it was doing as a theatrical prank, which is where I guess OP is getting the term lark. However, it was only a prank for those who assented to the racial dogma. For those on the margins of the southern racial systems–freedpersons and whites who worked with blacks and freedpersons–the Klan was terrifying. But terror lacks full explanatory power for understanding the Reconstruction Klan. Surely, if the Klan was just about terrifying those race traitors, then why bother with such elaborate robes? Wouldn’t pistols do the trick?
Indeed, the robes also derive from the minstrel tradition. Namely, the Klan was also about performance and theatrics. Thesis that argue that the Klan used such robes for the sake of concealing their identity are lacking. If they were trulyjust used robes for the sake of remaining anonymous, then why did they wear such elaborate robes, likes these? The robes were another indication of the theatrics. The Reconstruction Klan, unlike the Second Ku Klux Klan, did not standardize their uniform, but allowed for folks to build their own to fit the theatrics of the context. For example, in the most popular story about the Klan in the Reconstruction period, a Klanman kept a bucket between his legs, and then moved to drink a whole bucket of water, with the water filtering down to the bucket, to show that he was no mere mortal. But southern blacks were not the only ones with their eyes on the Klan.
The Klan also used theatrics due to the legal liminal space of Reconstruction. The Klan wanted to test the limits of reasserting political white supremacy, but the new found political reality of being reabsorbed into the Union was ambiguous. The Klan used their costumes to place them more into theater than politics in order to downplay their movement as a political movement. Indeed, a North Carolina Republican judge, in his historical novel, discussed the Klan as a “farcical,” stating that the Klan was “a piece of the broadest and most ridiculous fun.” For this judge, the Klan was not a political movement, but was in line with the minstrel tradition only.
(Without understanding these elements, we are left with a really superficial understanding of the Klan.)
I hope to be remembered for my atrocities! 
