I think you have to find a Threat Level 4+ planet, and dig down and hopefully stumble upon a flesh biome. https://starbounder.org/Flesh_Caves

The wiki for the basegame says they 'can' appear on most planets, their a deep underground mini biome, so you also need to take into consideration the size you might find has enough space to spawn enemies of other biomes nearby and not spawn enough or any of the flesh variety.

I'd suggest jungle, alien, radioactive and cold planets, that are really large planets too, and then just dig down 120 blocks and then start a 4 tile wide tunnel to the east or west till you find a large one.

Best places to find them will be Atropus worlds, Elder biomes. They will appear in other places too, but the two listed here are the most likely.

Originally posted by Sayter:

Best places to find them will be Atropus worlds, Elder biomes. They will appear in other places too, but the two listed here are the most likely.

Originally posted by Rain:

I think you have to find a Threat Level 4+ planet, and dig down and hopefully stumble upon a flesh biome. https://starbounder.org/Flesh_Caves

The wiki for the basegame says they 'can' appear on most planets, their a deep underground mini biome, so you also need to take into consideration the size you might find has enough space to spawn enemies of other biomes nearby and not spawn enough or any of the flesh variety.

I'd suggest jungle, alien, radioactive and cold planets, that are really large planets too, and then just dig down 120 blocks and then start a 4 tile wide tunnel to the east or west till you find a large one.

thank you both so much for the advice, it really helps.