Amanita hails from the planet Muscaria where its inhabitants are a fungus base species of humanoids. The beings from Muscaria have extremely long life spans. It is a widely circulated, yet unconfirmed rumor, that Amanita is even older then the Guardians themselves.

Amanita possesses a "cosmic awareness" that is said to be on par with that of the Guardians. It is unknown if this ability is natural to his species or is a power possessed only by Amanita.

He was originally recruited into the Corps by Larvox and Hal Jordan. Jordan had been tasked with rebuilding the Corps after the Guardians returned from their self imposed exile which followed the first destruction of the Central Power Battery.

Jordan agreed with Larvox assessment of Amanita, and though Amanita would be an ideal fit for Jordan's vision of a more well rounded and diverse Corps.

As a fungus based species, Amanita has a vastly slower metabolism then many Green Lanterns and takes a long time to accomplish simple things. Amanita has shown this when speaking with Guy Gardner and trying to say "Thank you".

However Amanita faired very well when he and the Corps battled Star Sapphire, suggesting that his speed does not limit him in his duties.

Amanita was not one of the Green Lanterns sent to stop Hal Jordan from destroying the Central Power Battery and had disappeared into anonymity. He later resurfaced among the many former Green Lanterns who were rescued from slavery by Guy Gardner.

Amanita rejoined the Green Lantern Corps during the rebirth.