For this challenge, we are given an image of Rick, from Rick and Morty, holding a gun being photoshopped onto an image from the video game, Fornite with a rift next to him.
The hint "wubba lubba dub dub" is a reference to a phrase said in Rick and Morty Season 1 Episode 11 meaning “I am in great pain, please help me”. This hint doesn't help us directly but they point towards us running the strings command on the image.
Command and Results: https://github.com/joeyjon123/riftCTF/blob/master/stegstrings1.txt
The flag is the very last output.
Flag: riftCTF{R1ck_4ND_the_r1ft}