There's often a final "e" in French, which is then changed to "eu" after the word gets reversed (and then often truncated). Another example is "herbe" (literally "grass" but now more often used for cannabis) which becomes "beuher" then "beuh"). As the final "e" is often mute, this process is then generalized even to words where it's not there. As a widely used example, a "flic" (slang for a "cop") becomes a "keufli" then a "keuf".