The FX item series are dynamic cosmetics that create a particle effect on the player that trail behind the player. These form some of the most popular expensive cosmetics alongside glowing eyes. These take the form of either an aura or a trail.
Auras[]
FX aura items create particles/effects around the players' whole body to form an aura. Currently only one aura is in the game.
Energy Aura[]
The Energy Aura item was the first cosmetic to have a dynamic effect beyond color swaps and glows, instead creating a particle effect of energy around the player. It was released for 600 coins on December 22, 2022.
The pale blue electrical energy particles produced aren't dissimilar to a stronger particle effect of those seen from the Stealth and Shield abilities introduced in the Halloween 2022 event.
Trails[]
FX trails are specifically tied to the player's feet and will only create particles if the leg moves from its previous position. This would include: running, jumping, falling, and emoting. They are the second "FX item", or aura—the first being Energy Aura.
Fire Trail[]
Before a naming scheme was known for this unreleased trail, players in the community colloquially referred to this cosmetic as "Fire Trail", "Blazing Aura", "Fire Aura", and similar terms. It was intended to release in v484 (Feb 1, 2023) but failed to reach the shop due to a communication failure between developers (the developer in charge of the shop was taken up with life and unavailable to manage things). At the time it would have been a Heroic cosmetic with a 600 
value just like other cosmetics of its type during the second market generation.
The current third market generation appears to mark cosmetics of this type as 1000 in value.
Ice Trail[]
The Ice Trail (Ice Trail FX as it was sold in the shop) is a counterpart to the Fire Trail. Original concepts for the cosmetic referred to it as "frostfire". It was sold for 1000 in the Shop during the Christmans holidays 2023.
It is unclear if it will sell every Christmas or was exclusive to the one year.
Slime Trail[]
The Slime Trail is another variation of the fire-like trails, this time using the color green. It was sold for 1000 in the Shop during the Halloween event in 2024. When equipped a trail of green fire follows the player's feet.
Players could earn this if they won the Halloween 2024 event (no antidotes required). Because of its availability to players as a prize, this is the most common of the FX items.
It is unclear if it will make a return.
Smoking Trail[]
UNOBTAINABLE — A trail of smoke follows the player. Can also be a trail of dust clouds kicked up, steam, snow, or other similar effects.
Pebble Trail[]
UNOBTAINABLE — Bits of debris are kicked up from the player's feet. These are very small pebbles that are hard to spot. It is the most subtle FX item in the game and can easily be missed if not looking closely.
Cloud Trail[]
UNOBTAINABLE — Large white clouds kick up from the player's feet. Similar to the white smoke trail above but larger and disappears sooner.
Glimmering Trail[]
UNOBTAINABLE — A shining array of stars follows the player's feet. The Christmas spirit can be felt in this one.
