Mega Ampharos may look terrifying, but it’s not very tough to counter. With an attack stat of 298, a Mega Amphoros can easily overwhelm teams with some electric-type moves.

It is a dragon-type Pokemon, which means it is weak against  Fairy, Dragon, Ground and Ice moves.

Also Read | Magmortar- type, strength, weakness, stats

Which Pokemon are strong against Mega Ampharos ?
Its biggest weakness is it’s poor movesets which are a boon for the trainers who want to beat Mega Ampharos in battle. Mega Ampharos cannot access any Dragon-type moves easily. Dragon Pulse is the move received by Mega Ampharos, but it was only through Community Day. It is not sure whether or not it would carry that move in a raid battle. 

Also Read | Leafeon- type, strength, weakness, stats

Opposing Dragons can sit unthreatened in front of Mega Ampharos because it likely won’t have Dragon move. Dragon-type Pokemon can win against Mega Ampharos in quick time. 
Shadow Dragonite is the best encounter to Mega Ampharos, in all available Pokemon. Shadow Dragonite has great Attack stats and it can spam Dragon Tail for a quick win until it charges up Outrage. Shadow Salamence is straight after Shadow Dragonite as a Mega Ampharos counter for the same reasons.

Also Read |Glaceon- type, strength, weakness, stats

To beat Mega Ampharos, Dragon Shadow and Shadow Pokemon are the quickest options. Garchomp is a great counter; it is a triple resistance to Electric moves. Mega Charizard X and Haxorus are also great counters, in addition Palkia is also a good counter which becomes a raid boss via the Ultra Unlock.

Also Read |Pokemon GO: Research Breakthrough Encounters in August

Fairy types of Pokemon are also good in this raid due to the all powerful Charm spam, for trainers who don’t have any Dragon Pokemon. Mega Amphoros can be defeated in a good amount of time by both Gardevoir and Togekiss.

Also Read | Pokemon Go: All you need to know about Pokemon Raid Day

Ground Pokemon are strong against all Electric-types, so it can do well here. Mamoswine has the benefits of using both STAB moves for super effective damage, even though the strongest moves to beat Mega Ampharos would be using Mud Slap and Avalanche.
Mega Amphoros can be easily destroyed by Excadrill and Rhyperior.