Pokemon Go has released approximately 75 of the over 135 Pokemon first introduced in Pokemon Ruby and Sapphire. That means we'll see 60 more Pokemon get released into the wild over the next few weeks/months.
Some of these unreleased Pokemon will be nothing more than Pokedex filler, Pokemon that players catch for the XP and Stardust and then promptly transfer away. However, some of these Pokemon are expected to be among the strongest in the game and could radically shift which Pokemon players see while attacking or defending gyms.
So which Pokemon should players be on the lookout for? Here's some of the best Pokemon still to come in Pokemon Go:
Metagross is the strongest non-Legendary "Gen 3" Pokemon, and it isn't even close. This Steel/Psychic powerhouse is expected to become both a top attacker AND a top gym defender when it finally gets added to Pokemon Go. While Metagross's attack stat isn't in the same tier as Legendary Pokemon like Groudon or Kyogre, it's still comparable to Pokemon like Dragonite and Gengar, both of whom are considered some of the best Pokemon to bring into battle.
What's really impressive about Metagross is its great Defense. While a 247 Defense isn't in the same tier as Pokemon like Steelix or Cloyster, its resistant to most attacks thanks to being a Steel-Type AND it can wallop a punch unlike most top tier defenders.
Metagross will have its weaknesses, but this is definitely one of the Pokemon that you'll want in battle. Best of all, Metagross has both Steel and Psychic moves in its movepool, so you'll even be able to optimize this Pokemon depending on whether you want a top-tier Steel-Type attacker or another solid Psychic-Type Pokemon.
Salamence could finally overtake Dragonite's long-held role as the top generalist in the game. Players have long prized Dragonite for its lack of weaknesses, general bulkiness, and strong attack, but Salamence could present an intriguing alternative. Salamence is a Dragon-Type Pokemon just like Dragonite AND it has higher Attack and Stamina stats, albeit at the cost of some Defensive strength.
What really separates Salamence from Dragonite is its ability to use Draco Meteor, one of the newly added moves in Pokemon Go. Draco Meteor has a base damage output of 150, and it gets boosted to 187 thanks to the same type attack bonus. Draco Meteor will be the strongest Dragon-Type attack, and Salamence is the only Pokemon that can use it.
Dragonite will still have some use as a superior defender, but Salamence should overtake it as the best Dragon-Type attacker in the game. And that will probably be pretty useful considering that three of the upcoming raid bosses (Rayquaza, Latios, and Latias) are all Dragon-Types with only a handful of weaknesses.
Aggron is basically Steelix with a bit more bite. This Rock/Steel-Type Pokemon has comparable Defense and Stamina stats to the massive rock snake Pokemon, but Aggron has a much higher attack stat, which makes it more viable as a gym defender.
Unlike Metagross and Salamence, Aggron probably won't bring cataclysmic changes to the Pokemon Go metagame. Aggron will probably rank better as a gym defender than Rhydon or Golem, but its Stamina stat is pretty low, which means that it won't have a ton of HP. A few well-timed Water or Grass-Type charge moves will knock Aggron on its butt in a hurry, just like any other Rock-Type Pokemon you face in gyms. Aggron also doesn't have any pure Rock-Type movesets, which also limits its effectiveness in raids where Rock-Type Pokemon reign supreme.
Flygon and its pre-evolutions don't have the gaudy CP stats that the other Pokemon on this list have, but it could make its own impact in Pokemon Go.
Let's start with the basics: Flygon's max CP is 2458, which puts it in the range of Pokemon like Poliwrath or Scyther. Those are both respectable Pokemon, but not what you're looking for to anchor any sort of raid or gym team. Flygon could be a bit useful as a budget Dragon-Type Pokemon, as it has access to both fast and charge Dragon-Type moves.
Where Flygon really shines is that it could help a LOT of trainers make progress on their Dragon-Type medals. Players get medals for capturing or otherwise obtaining types of Pokemon, which make it a bit easier to catch those types of Pokemon in the wild. And while most experienced players have almost all of the medals, many are still missing their gold Dragon-Type medal due to the general rarity of Dragon-Type Pokemon in the game.
Trapinch isn't a Dragon-Type Pokemon, but it'll evolve into the Ground/Dragon-Type Vibrava for just 25 Candies. So, if Trapinch is a relatively common Pokemon, it could be the key to getting that Dragon Medal...which will then make Rayquaza and other Dragon-Type Raid Bosses a bit easier to catch later this year.