Animal Friend

Animal Friend is a Fallout, Fallout 3, Fallout: New Vegas and Fallout 4 perk.

Fallout
In Fallout, with this perk, some animals will not attack the player character, unless the animal is attacked first. This perk applies to all forms of rats and radscorpions except those in Shady Sands' radscorpion caves.

Fallout 3
With the first rank of this perk, animals will simply not attack the player character. With the second rank, these creatures will come to their aid in combat, but never against other animals.

This perk affects:
 * Mad brahmin
 * Mole rats
 * Vicious dogs
 * Yao guai

Additional dialogue
A new dialogue option becomes available when speaking to Tree Father Birch in Oasis. He will then explain to the Lone Wanderer why there are many animals in Oasis and how they are attracted to the sanctuary, though this doesn't have any benefits other than a little backstory of Oasis.

Fallout: New Vegas
With the first rank of this perk, animals will not attack the player character. With the second rank, these creatures will come to the character's aid in combat, but never against other animals.

This perk affects:

Additional dialogue

 * In The Fort, this perk makes it possible to bypass the fight with Antony's dogs to get back Sergeant Teddy by telling him that animals are friendly to the Courier so the dogs will not attack. He will remark that he thought there was something wrong with his dogs, as they usually have to be pulled off new visitors to the Fort, and since the fight would not be fun, he will just give up the bear.
 * During the main quest You'll Know It When It Happens, the search dog can be taken from the ranger, allowing the player to find the disguised engineer.
 * After Borous has been given Gabe's bowl and told that Gabe has been put down, this perk gives the option to express understanding of his feelings for the cyberdog.

Fallout 4
Affecting an animal requires looking down a weapon's sights and pressing the confirm/use button. Success will be indicated with an animation, whereas failure will result in a notification. Once one has made an attempt on an animal, they cannot immediately make a second attempt. One must be within a certain range of the animal to pacify it, while Inciting/Commanding requires an even closer range. This perk affects the following animals (list may not be complete):