What is the rarest Shadow Pokémon?

The rarest and most coveted Shadow Pokémon is Shadow Mewtwo. This powerful Mythical Pokémon is only available periodically when defeating Giovanni in Special Research, making it extremely limited. Given Mewtwo‘s unmatched performance as the #1 counter for many Legendary raid bosses, Shadow Mewtwo stands in a league of its own when it comes to rarity and strength.

As a Pokémon GO trainer, we all dream of adding this exclusive Shadow Legendary to our collections one day. Let‘s explore what makes Shadow Mewtwo and other Shadow Pokémon so rare and desirable.

How Do Shadow Pokémon Work?

Before diving into specific species, it‘s important to understand what gives Shadow Pokémon their unique qualities in Pokémon GO.

Shadow Pokémon originate from Team GO Rocket invasions. They are regular Pokémon that have been corrupted by some mysterious technology, causing them to emanate a dark aura and become more vicious in battle.

These Shadow Pokémon gain a +20% damage bonus to their attacks, making them fearsome glass cannon attackers. However, the tradeoff is that they also take +20% increased damage from incoming attacks.

In addition, Shadow Pokémon cost significantly more Stardust and Candy to power up compared to their normal versions. They start with the move Frustration, which prevents learning special event-exclusive Charged Attacks.

Fortunately, you can "purify" a Shadow Pokémon to remove their Attack bonus and Defense penalty. This also reduces their power up costs and allows them to learn legacy moves. Purification grants +2 IV points to each stat, making it a path to perfection.

So in summary, Shadow Pokémon are risky, costly investments with big payoffs for your effort. They represent the next level of power beyond regular Pokémon. Now let‘s get into what specific species stand out as the rarest finds.

Factors That Make a Shadow Pokémon Rare

When determining which Shadow Pokémon qualify as the rarest, there are a few key factors that contribute to their elite status:

• Limited Availability – Some Shadow Pokémon are only available for short events or small time windows, making them extremely scarce afterwards. Species tied to Team GO Rocket Leaders like Cliff can also have limited availability depending on the rotation.

• Egg/Raid Exclusivity – Many rare Shadow Pokémon can only be obtained from Eggs or Raids. For example, Beldum and Bagon are 12KM Egg exclusives, while Mewtwo can only be found by defeating Giovanni.

• Shiny Potential – Shiny Shadow Pokémon, affectionately called "Shundos" are extra rare prizes due to standard shiny rarity at 1 in 500 base odds. Even non-shiny perfect IV (Hundo) Shadows are uncommon.

• High PvP & Raid Viability – Shadow Pokémon with optimal stats and movesets for Go Battle League, Master League, and top raid counters increase their utility and value.

Let‘s now look at some of the rarest and most coveted Shadow Pokémon trainers should be on the lookout for based on the above criteria.

The Absolute Rarest Shadows

Shadow Mewtwo

Without question, Shadow Mewtwo reigns supreme as the single rarest Shadow Pokémon in the game. Here‘s a quick rundown of what makes this Mythical so special:

• Availability: Exclusive to Giovanni Special Research
• Rarity: Tied to limited-time Rocket events
• Stats: 300 Attack is unmatched. Can reach 4,398 max CP
• Moves: Can learn any Charged Move. Best with Psystrike
• Performance: #1 Counter vs. Psychic, Ghost, Fighting raid bosses

I cannot emphasize enough how incredibly rare and valuable Shadow Mewtwo is in Pokémon GO. It is exclusively available through Giovanni Special Research, which only comes around a few times per year. Scoring this Shadow Legendary is essentially a lottery ticket for any dedicated trainer.

And not only is Shadow Mewtwo insanely rare…it‘s also the single best Pokémon to use against the toughest raid bosses like Mewtwo, the Swords of Justice, and more.

That 20% attack bonus makes a WORLD of difference, allowing it to surpass Mega Gengar and Mega Houndoom as the #1 Ghost and Psychic type attacker.

Having a Shadow Mewtwo is essentially a flex and long-term investment. You may never get another chance, so make the most of this powerful specimen!

Shadow Metagross

Next up is Shadow Metagross, which can only be acquired via 12KM Team GO Rocket eggs. Here are the key points on this Shadow pseudo-legendary:

• Availability: Team GO Rocket 12KM Eggs only
• Rarity: Shiny capable, estimated 1 in 60 rate
• Stats: Reaches 3,791 max CP. Excellent for Master League
• Moves: Meteor Mash exclusive move is ideal
• Performance: Top Steel-type attacker. Premier PvP pick.

The Beldum line is highly desired for having the absolute highest stats among non-legendary species in Pokémon GO. A perfect IV Shadow Metagross is a true prize.

Being egg-exclusive with shiny potential makes hatching these monsters from Rocket Leaders a rollercoaster. An elusive 100% IV shiny would be the pinnacle – a "Shundo" collector‘s dream!

In PvP, Shadow Metagross exceeds 4,000 stat product when purified to 100% IVs, making it one of the best picks in Master League where you want high CP and survivability.

It‘s also arguably the #1 Steel-type raid attacker when factoring in Mega Evolution. Definitely invest in this supercomputer Pokémon!

Shadow Legendary Birds

No list of rare Shadow Pokémon is complete without mentioning Shadow Articuno, Zapdos, and Moltres. Here‘s a quick profile:

• Availability: Giovanni rewards, very briefly
• Rarity: Mythical and shiny capable
• Stats: High CP, unique typings
• Moves: Signature moves are best (Hurricane etc.)
• Performance: Strong in raids and PvP

These Legendary birds tick all the boxes for rarity. They‘ve only been available for brief 1-2 month periods after defeating Giovanni. Their shiny versions are even rarer prizes.

Unlike Mewtwo, their base stats cap out a bit lower in the 3,000s. But that 20% attack bonus gives them greater potential to do big damage with their unique typings. Moves like Zap Cannon and Hurricane let them stand out.

While not necessarily the #1 options for raids, these Shadow birds are collector‘s items and can still perform well in Master League and raids when you need their types.

I‘ll never forget finally getting a Shadow Zapdos – it felt like catching a little bit of lightning in a bottle. Hopefully we‘ll see more of these Shadow Legends returning in 2024!

Other Notable Rare Species

Beyond the top 3 rarest, here are some other Shadow Pokémon that are highly coveted:

• Shadow Salamence – Rare dragon grunt find, amazing attacker
• Shadow Tyranitar – Discontinued, superb rock type raider
• Shadow Snorlax – Tanky gym defender when purified
• Shadow Machamp – Strong fighting type, Cliff/grunt exclusive
• Shiny Shadows – Any species with 1/65k shiny odds
• Perfect IV Shadows – Those with max stats for PvP & raids

The list goes on. But the main takeaway is look for Shadow Pokémon that have exclusive or limited means of obtaining them, are viable for combat, and have IVs/shininess that provide collector value.

Hunting These Rarities

So how can you maximize your chances at catching one of these ultra rare Shadow Pokémon? Here are some tips:

• Keep an eye out for Team GO Rocket events or new Giovanni Special Research releasing – capitalize on limited time Shadow Legendaries!

• Battle the Rocket Leaders daily and hatch every 12KM egg you get – Metagross and Salamence are in the pool.

• Target high level/weather boosted Shadow Pokémon with strong appraisals – they have high IV potential.

• Trade Shadow Pokémon to reroll IVs and hopefully get a Shundo or 100%. Getting lucky friends first raises the chances.

• Purify Shadows with 13/13/13 or higher IVs to turn them into perfect 4* specimens.

• Check your local Discord/Facebook groups when rare Shadows get spotted for callout raids.

• Follow reliable sources like Serebii and Pokémon GO Hub for event dates and news.

The thrill of chasing these rare Shadow Pokémon keeps the hunt exciting. With perseverance, you can score these powerhouses through patience, preparation and community support. Wishing you the best of luck in securing that coveted Shadow Mewtwo or surprise Shundo! Stay determined and remember to have fun during the journey of building your elite Shadow roster.