Hydra rhymes with:
wydra, adra, alessandra, alexandra, ardra, bavadra, bondra, calandra, cassandra, chandra, condra, cuadra, d'alessandra, deidre, deirdre, diedre, double-entendre, edra, entendre, hendra, jayachandra, jindra, kendra, letendre, lysandra, madra, mahindra, mudra, navin-chandra, pachysandra, phedra, piedra, quadra, saavedra, sabedra, sandra, satyandra, saundra, savedra, sciandra, sidra, skudra, sondra, tundra, vondra, wondra, wydra, zandra
Hydra sounds like:
hader, hadria, haider, hater, hatter, hattery, hattori, haueter, hauter, hayter, header, headwater, heater, heather, heathrow, heeter, heider, heidiwear, hider, hither, hitter, hodder, hoddur, hooter, hotter, hotwire, huether, hutter, hyder, hydro