Trails are particles that are generated on your body as you move around. They are purely cosmetic and are unlocked via crates, events, etc.
Hearts - Unlocked by becoming a level 3 Patron.
Spark - A prize from the Vote Crate (Since 21 Apr 2019)
Spring - A prize from the Spring Crate (April-May 2019)
Lava - Admin Trail
Infinite - A prize from the Infinite Crate (Since 22 Jun 2019)
Summer - A prize from the Summer Crate (May-Aug 2019)
Spooky- A prize from the Spooky Crate (Sept 2019- )