The Blumbus Dimension is a dimension where humans celebrate Blumbus instead of Christmas. This dimension is very similar to other dimensions, except it allows for cannibalism during its Blumbus celebration and it has a powerful interdimensinal being, Mr. Chimney as a celebrated figure. It only appears in Rick and Morty Issue 8.
Blumbus is a yearly celebration held in this dimension during the winter-time. People typically wear Blumbus(/Christmas)-sweaters, decorate trees and do their holiday shopping. The two central figures in Blumbus are:Mr. Chimney (their version of Santa) and Cheeky the Snowguy (their version of Frosty the Snowman), both creepy versions of regular holiday figures. Almost all bars are typically closed on Blumbus.
Truthsteak McGloin is worshipped on Blumbus as the people's lord and savior. He was a human who referred to God by the wrong pronoun and therefor turned into a pineapple so he could share his sweet juice with the world and be cleansed of all sin. He has a church based around his faith.
The Blumberflarg is essential to every Blumber celebration. A blumberflarg is where you find a lonely teenage boy on the street on Blumbus eve and invite him back to your house so you can mate with them and then eat them. It is considered a time-honored tradition, but has changed during the years to people just buying their blumberflarg (lonely teenage boy) from the store instead of going hunting for them. This is presumably done against the boys' own will.