The Weird Shell Jump is an advanced trick used in Super Mario Maker and is probably the least well known variation of a shell jump. It is widely considered to be one of the most difficult to pull off tricks in the game.
How It Works
The Weird Shell Jump uses the same mechanics as the infinite 1-Up shell trick, except in midair. When a shell is a certain distance from a wall Mario can bounce on the side of it while also kicking the shell forward.
Because Mario is not technically jumping on the shell, performing a Spin Jump or Yoshi jump will not destroy the shell. This also means Mario is able to jump off a Spiny shell without taking damage. This will also cause Mario to bounce 1 block lower than he would on a regular shell bounce.