What is legendary event of 2018?

Friends I read the news of legendary event of 2018 .But I don’t understand so can explain me what this event actually?

You will be able to get certain Legendaries for Sun/Moon/Ultra Sun/Ultra Moon. Look here for more information:

https://www.pokemonlegendary.com/en-us/

It is suspected that this special event could influence Pokémon Go somehow but there are no information about it yet.

That means it is chance to Catch raikou ,entei,lugia by raids once again is it.

Nobody knows. We just have to wait, maybe till summer.

And carry I have one question what is quest system? I heared that in quest system if you Catch 10 ice pokemon and walk 20 then you have to chance to Catch articuno Is that true?

That’s nothing official from Niantic, it’s just an idea from the playerbase. In most online games you have to do quests to gain special rewards. Since Pokémon Go doesn’t have such system it would be refreshing new if Niantic would do something like quests to gain Legendaries.

But again, it’s not confirmed in any way. Just some wild speculating.

In the core games series, a monthly distribution system is taking place from February to November, using the following schedule:

February – Dialga & Palkia in GAME in the UK & Gamestop in the US
March – Regigigas and Heatran
April – Raikou and Entei
May – Xerneas & Yveltal
June – Shiny Zygarde
July – Tornadus & Thundurus
August – Kyogre & Groudon
September – Latios & Latias
October – Reshiram & Zekrom
November – Ho-Oh & Lugia

What is meaning of it?

If you have the game(s) Sun, Moon, Ultrasun and/or Ultramoon for Nintendo 3DS you have the possibility to download those Legendaries each month, via Internet or Code.

Nothing relevant for Pokémon Go.

This is possible in pokemon go game or not?
I want entei ,Raikou is that possible by this event in pokemon go game?

I think that has to do with the regular games for the 3DS. Not Pokemon Go.

No, it’s not possible for Pokémon Go.

But is it possible to Catch legendary dogs and legendary bird in future by raid,events, and by any other method?

No