Under achieving or unrecognized heavyweights.

[Warlord]

If we're talking obscure, fringe heavyweights who could've possibly made some noise in today's era, I think Jo el Scott probably deserves some mention. He's among the worst pieces of shit ever to lace up a pair of gloves, but he could hit like a truck.

Jimmy Thunder and Jeremy Williams might also get a mention, though both are a bit more well known than Scott, I reckon.