Celebi: You don't.
Gible: Breed any of the Garchomp line.
Gible evolves into Gabite at level 24.
Gible evolves into Gabite at level 24.
on route10
There is no other way unless you want to trade
You can get Gible in the Safari Zone in Pokémon HeartGold in the Rocky Beach area however it'll only appear there after you have placed 13 Plain Objects and 17 Peak Objects there and after you have waited 100 days.
I suggest you try playing Pokemon Beige Brown instead, it is far superior.
Answergible is not really is you know how to get into the rare seceret entrence to wayward cave under the bike path right under the first guy catching gible without cheats is hard but finding him is easy
Gible is not available in this Pokemon version in the wild. to acquire Gible, you must beat the Elite Four and transfer this Pokemon through the Poke Transfer Lab located on Route 15. You must have Gible in your PC in another Pokemon game used on a DS (Diamond, Pearl, Platinum, Heartgold or Soulsilver.) This is true for all Pokemon you want/need in previous generations.
No the only way to get Gible, is to get him in a trade or the safari zone
Garchomp is obtained by evolving Gabite. Gabite evolves into Garchomp at level 48. To get a Gabite, you must first have a Gible. Gible evolves into Gabite at level 30.
you can get gible in the safari zone but to get gible shiny you need to breed a gible whit a ditto but you need a Chinese ditto
Gible is a Dragon and Ground type pokemon.