Besides retaining any abilities that the previous Rayquaza under it had, it also adds a few of its own to the mix
So, the Boros Mousefolk archetype appears aggressive and wants to use a lot of combat tricks to fight when they absolutely have to
Unless the card in question is an instant or a sorcery type, that text will be divided up into individual abilities, describing the effects it has while in play or (more rarely) when in another zone like the hand or graveyard
In response to the game's dominant meta strategies, one fan sought to improve the game's balance with an original concept for a Pokemon tool card
It has a good rate and can be played in Saproling EDH decks like Slimefoot, the Stowaway or Slimefoot and Squee
The best thing about this combo is that it doesn't use up any of your resources like the Azusa and Walk the Aeons combo