- Aydra (Technical Death-Italy) - Outro nome : ex-Hydra
- Luctus Hydra (Black Metal-Chile) - Outro nome : Hydra
- Hydra (USA) (Southern Rock-USA) - Outro nome : ex-Noah Mayflower, ex-Osmosis
- Hydra (PL) (Stoner Doom-Poland)
- Hydra (GER) (Symphonic Metal-Germany)
- Hydra (JAP) (Heavy Metal-Japan)
- Hydra (FRA) (Heavy Rock-France) - Outro nome : Hÿdra
- Hydra (MLT) (Power Metal-Malta)
- Hydra (ESP-1) (Heavy Metal-Spain)
- Hydra (ESP-2) (Power Metal-Spain)
- Hydra Head 9 (Industrial Metal-Sweden) - Outro nome : HH9
- Hydra Kyll (Metalcore-USA) - Outro nome : HK
- Hydra (SWE-1) (Melodic Death Black-Sweden)
- Hydra (SWE-2) (Hard FM-Sweden)
- Hydra Vein (Thrash Metal-United-Kingdom)
- Hydra's Fate (Melodic Power-Germany)
- Hydraform (Progressive Metal-USA)
- Hydranight (Symphonic Metal-Netherlands)
- Hydrarrgyrum (Death Metal-Czechia)
- Hydrawolf (Melodic Death-USA)