Vampire: The Masquerade - Swansong

As the description states, you'll need to sate your hunger by feeding on a rat. The first time you can earn this trophy is relatively early on, in Emem's first solo level, Scene 04: Emem – "Unknown" (Jefferson Library). 

After you've finished Scene 01 (see A gathering of beasts ), you'll be given the option to play as one of the 3 playable characters. You can do these in any order you want. Once you start Emem's level, the Scene begins with her locked in a prison, desperately hungry. Look around the room and you'll find a rock on the floor by the left wall (facing the door). Press to examine it and 3 rats will come running out. Feed on all 3 so that you can replenish your Hunger and drop it down to 2 purple drops. As soon as you feed on the first rat, this trophy will pop.

While the game will tell you that feeding on rats will increase your Suspicion meter, you can safely ignore that. Despite eating many rats throughout the entire game and remaining high on the Suspicion meter, nothing ever happens and it's nigh impossible to actually reach the end of the meter. Plus, once you've eaten enough rats, you get bonuses that greatly negate the additional Suspicion, all the way up to completely erasing it entirely.

In addition, it's far better to gain additional Suspicion or a negative trait than it is to max out on your Hunger and lose control of "the beast" and kill something, so you should definitely feed on them if your Hunger meter gets high, and don't worry about any negative effects.