Mellgren rhymes with:
helgren, ahlgren, halgren, hallgren, helgren, ahlgren, almgren, berggren, bergren, blomgren, cedergren, edgren, elvgren, forsgren, halgren, hallgren, helgren, holmgren, hultgren, lagergren, landgren, liljegren, lindgren, lofgren, lovgren, lundgren, lungren, malmgren, nordgren, nygren, ogren, ostergren, palmgren, rosengren, sandgren, seagren, shogren, sodergren, stromgren, westergren, youngren
Mellgren sounds like:
mailgram, milacron, milgram, milligram, mulkern