Retarculous was originally coined by To Catch a Predator decoy, Emily Bicks. It is a conjunction of 'Retarded' and 'Ridiculous.' It is used to describe something that is extremely dumb, stupid, etc.
( a combination of the words retarded and dangerous) : something that is, according to most normal people, both retarded and dangerous, however one is to define the terms.
Even if done f-sag, goingassbogganing down the stairs into your basement on a mattress is still retargerous imho.