From an email from Charlie Hunt:

I noticed we have a mis-spelling of humongous in:
./vm/gc/g1/g1RemSetSummary.cpp
  RegionTypeCounter _humonguous;
  HRRSStatsIter() : _all("All"), _young("Young"), _humonguous("Humonguous"),
      current = &_humonguous;
    RegionTypeCounter* counters[] = { &_young, &_humonguous, &_free, &_old, NULL };

Also note the variable name also happens to be misspelled too. But, that's probably not as as annoying as when you see the mis-spelling in G1 log output.

This mis-spelling of humongous shows in summarized RSet out produced by G1SummarizeRSetStats.