Modifiers matching tetrapod:

• aquatic,
• terrestrial,
• amphibious,
• modern,
• poikilothermic,
• herbivorous,

Simple categories matching amphibious:

• creature,
• vertebrate,
• decapod,
• being,
• animal,
• reptile,
• tetrapod,
• mammal,
• friend,
• inhabitant,