noun
giant tortoise
Refers to large land-dwelling tortoises, especially those of the Galápagos and Aldabra species.
ガラパゴス諸島には大きなゾウガメがいる。
There are large giant tortoises in the Galápagos Islands.
亀 is the general word for turtle/tortoise; ゾウガメ specifically refers to giant tortoises.
Compound of 象 (ぞう, 'elephant') and 亀 (かめ, 'turtle/tortoise'), referring to its large size.