‘Luvall’s Monster’ [C. mollissima × (C. crenata × C. dentata)] is a first-generation seedling of one of two old, putative Japanese × American hybrids growing on the Mississippi River in Dallas City, IL. Its pollen parent is unknown. The cultivar grows vigorously and with a preferred open crown architecture. It is also pollen-sterile, which makes ‘Luvall’s Monster’ exceedingly high-yielding. The nut is twice as large as that of its mother. It also has a great flavor, raw or roasted, and the pellicle often comes off the kernel in one piece. However, the nut is quite wide, does not store well, and has frequent double embryos and splits. There is also a tendency to develop a “hollow heart,” which is typical of Japanese and American nuts. Scion and OP seedlings have been widely circulated among Northern Nut Growers Association members. Grafts of the tree were tested in Byron, GA, to determine gall wasp resistance and the effects of climate on nut size. According to B. Caldwell, the tree does bear well in upper New York state, with good-size nuts for that area. More testing is needed in short-season areas (Hunt et al., 2004; Miller, 2017; Nave, 1998).