This slow growing giant size (34 inches high by 65 inches wide) hosta of H. 'Sieboldiana' breeding was introduced by Paul Aden of New York in the 1980's and registered by Peter and Jean Ruh of Ohio in 2010. According to the Field Guide to Hostas by Mark Zilis (2014), "...formerly thought to be a Paul Aden origination, but originator now considered unknown."

Its leaves are deep blue-green early but change to dark green later in the season. The foliage is moderately corrugated and generally unruly in habit. Near white flowers open from mid-June into July and form numerous seed pods.

According to The Hostapedia by Mark Zilis (2009), "Whenever I'm asked to identify the best big blue-leaved cultivars, 'Blue Mammoth' always comes to mind (with 'Blue Angel')."
 

An article by Warren I. Pollock in The Hosta Journal (2000 Vol. 31 No. 1) states that, "H. 'Blue Mammoth'...The hosta's name has blue in it, but the leaf looks mighty green in the article's photo."