Scorpion

Reaching tier 100 of the Season 2 RNG Pass was the only way to get Scorpion, and the pass has ended, so the wiki lists it as unobtainable now. It arrived with Eon 1-7 and was never part of the roll table, which means there is no odds figure to quote. It is also one of the few auras in this group with a real moveset, so it was a combat reward as much as a cosmetic one.

According to the wiki, the player takes a defensive stance with a giant scorpion tail on the back and a small scorpion on the left arm, both tails glowing gold at the stinger, with sand rising from the ground. The abilities are Dash on Q with a 3 second cooldown, StabScorpion on R with a tail sting worth 25 total damage, Tailswing on X, a 360 degree spin for 5 damage, and Sandstorm Punch on E, a lunge plus bite for 12. Four creators are credited: Letaw_66l, Angel_CrepUltra, meltedwaffled and Zyndreon.