If you're confused like "they never even interacted, why did you draw this?" well...they may actually interact in the next episode named "wizard city". just look; https://media.discordapp.net/attachments/345696565270151169/797183062517088356/unknown.png https://static.wikia.nocookie.net/adventuretimewithfinnandjake/images/f/f6/ATDT_final_poster.png and I'm hoping they can be friends, i like both of these characters and pep is one of my top favourites.~ I'm like being early by drawing them together, let's see how accurate this picture will be to the canon. my hopes for the next episode; it won't be a prequel, pep will turn back to normal and stay that way, pep and abracadaniel will be friends, pep backstory, it will be a great and fun episode in general. 

if you're thinking "that's not how rainbow colours are!"; https://static.wikia.nocookie.net/adventuretimewithfinnandjake/images/3/37/S5_e26_Starchy_gets_his_wish%2C_sort_of.PNG