If you're having issues with completing the "Wildlife Photographer" achievement, then this guide is for you. Keep in mind, this guide only focuses on acquiring a photo of the Purple Crybaby monster. Spoilers of the game below.

Guide:
The purple freaky thing dies when you take its photo; thus, a workaround is necessary. By taking a photo from afar, when it's not looking or too far to die to the flash, you can catch it on camera without killing it.

Steps:
1: Find the purple scumbag (catacombs, for example)
2: Stay away from the alien, or he'll snitch to the feds hunters
3: Pull out your camera, *not the selfie stick* (hope you brought a battery cell)
4: Wait until he is sideways facing away from you/so far away that he can look at you and you won't get caught
4: Photograph him like one of your French girls <3
5: Varied measures of success ???
6: Assuming you failed, try to keep your flashlight on when you're far away
7: If that doesn't work, take a photo from behind the door in the catacombs while holding it open (make sure Lovecraft Barney faces you)

To better visualize what the end result should be, I've provided the photo that nabbed me the achievement.

In theory, this should nab you the achievement (assuming this was your last photo needed). With some patience, you should be able to pull it off. Good luck.