The Omori is a grey metal weight in the shape of an isosceles trapezoid and is a little larger than half of Tails' height. It has a handle on top and the text "10t" written on the front. Given the text written on it, the Omori supposedly weights ten tons.
In gameplay, the player can latch onto the Omori with Tails' Ring by pressing the 1 or 2 button and can let go of it by pressing the 1 or 2 button again. When latched onto the Omori, it will force the player to slowly drag it along the ground, deducing the speed of Tails' forward movements. If the Omori is dragged over a ledge and falls down, Tails is pulled down with it. This is a good way to quickly descend from midair.