This achievement is obtained through making certain political decision. This problem will be brought by lizard ambassador and will be about undead taming the fangbears. To get both achievements for this decision save before making decision and reload.
*** Spoiler - click to reveal ***Lizard ambassador will bring forth the problem of undead taming the fangbears as pets which is dangerous. To get this achievement you need to make negative decision to put down fangbears. But you need to know that this decision will make -5% damage to your population.