The new and distinct hybrid of Heuchera plant named ‘；Mahogany Monster’； with very large foliage having rounded apices and lobes, leaf blades begin the season deep glowing red and develop to dark mahogany without silver overlay surrounding the veins. Numerous, densely-branched, stiff, erect, very large, wine-colored panicles display bright pink calyces with near white petals for about five weeks beginning late spring and repeating through the summer. The new plant is vigorous and produces large broadly-mounded clumps.
