Lore

One day Oliver,Zip,and Edward where in the science lab and where screwing around in the science lab when Oliver had an idea what if they make a creature out of their DNA and Zip and Edward thought this was a great idea so Edward using his intelligence created a machine that could do that out of the supplies in the science lab and put there DNA into it little did Zip and Edward know that Oliver had been hitting it up with Alice for the last 4 hours so when he used his Saliva it had Alice's DNA in it so when it came out it looked like Goober but it didn't attack them it instead asked "are you my parents" and the gang just looked at it but then Zip said "Can we keep it" so Goober basically became there pet and also thanks to Alice's DNA can shapeshift and is basically a Skinwalker.