Learning Greek

I'm making a monster name generator for my game. Traditionally video game monsters have Greek names. So I need to know basic Greek inflection rules to turn noun into an adjective, suitable for monster name. For example greek word for gold is "chrysos" (yes, Jesus Christ got greek surname). Now would "chrysis" be the correct word for golden? Now Google Translate claims it is chrysafenous, but I'm dead sure the ancient Greek word for "golden" is "chrysis", and google translate also translates "chrysis" as "golden". WTF is with that chrysafenous?