A lot of Pokemon names in English are puns. Like Treecko (tree/gecko) or Bulbasaur (a plan bulb + dinosaur)
I figured it may be the same with the Korean names.
Treecko / 나무지기
나무 is tree, but what about 지기? Turns out 지기 isn’t a noun; it’s a play on 지키다, a verb meaning ‘to protect’. So essentially, 나무지기 means ‘tree guardian’.
Grovyle / 나무돌이
나무 can be seen in this name, too. It’s a common theme with all 나무지기’s evolutions.
Ok so 돌이. 돌이 is the male equivalent of 순이. These are both endings that are ended to the end of a type of person. It tends to be used in 2 cases. One case is when a person is very deep into their field, career, or a situation. The other case is when 돌이/순이 is used as a cute nickname. In the case of 나무돌이 its a cute nickname. This is complicated, so here’s some further examples:
Ignore the 쟁이, I forgot to crop it out
Sceptile / 나무킹
This one is easy! Just 나무 + 킹. 킹 is just Konglish for ‘king’. So 나무킹 is ‘Tree King’.
The Korean word for king is 왕, but for the pokemon they chose to use Konglish.
나무 = tree
지키다 = to protect
킹 = Konglish for ‘king’
왕 = king