Heatran is double typed: fire and steel. And both types are weak to Ground types! Double Weakness! So this list will be dominated by Ground types. The list of top DO@20 counters for Heatran are:
- Groudon: Mud Shot / Earthquake
- Rhyperior: Mud Slap / Earthquake, Surf
- Rhydon: Mud Slap / Earthquake
- Swampert: Mud Shot / Earthquake
- Flygon: Mud Shot / Earthquake
- Golem (Normal): Mud Slap, Mud Shot / Earthquake
- Machamp: Counter / Dynamic Punch
- Kyogre: Waterfall / Hydro Pump
- Donphan: Counter / Earthquake
- Blaziken: Counter / Focus Blast
If you don't have enough ground types, fire and steel are also vulnerable to fighting, fire, rock, and water. For Heatran, fighting and water types complete the top 10. If you need a longer list, please follow the link above for the entire list.
Other Lists
Take a look at this list of top Heatran counters It is closest to DO@14 list of best Pokemon against Heatran. Take a second look at these Pokemon that appear higher on DO@14- #7 Heracross: Counter / Earthquake
- #12 Toxicroak: Counter / Mud Bomb
- #14 Zangoose: Fury Cutter / Dig
- #15 Sharpedo: Waterfall / Hydro Pump
Other move sets
If you're looking for other move sets, here is the list of top DO@20 Pokemon vs Heatran, showing multiple moves. The option is on the right side is unchecked.If you have any comments or suggestions, please visit this Reddit thread