AU
Setting: modern
Summary: Eren saves a tiny mouse (or baby rat?) Arian from becoming snake food at a local pet store. He’s instantly like a nervous but enthusiastic new father, reading up on how to take care of mice and buying all the best things for him even though he has to make his paycheck stretch. Eren and Arian bond so deeply that Arian becomes a magical animal (through the power of ~love~), quickly adapting to a mindset of around 16-20 years old, which would have been his age in mouse years. He stays that way and continues to age at a human pace, giving him a prolonged lifespan.
In addition to becoming sentient (basically indistinguishable from a normal human teenager though he lacks in a lot of basic knowledge at first), Arian soon becomes able to change into a human form - though only partially at first. The first form he gets is only slightly more human, and only about twice as big as his mouse form (Anthro), and still can’t speak human language in it. But he continues to find new forms that get increasingly more human in increments, and can choose to change into any of them, including back into a normal mouse.
As soon as Eren realizes Arian is sentient, he blows all of his money on dollhouse stuff, which is the perfect size for him in his anthro form. Arian then lives with open cages and little dollhouses, coming and going as he pleases but Eren keeps adding panels to walls so Arian can get around without going on the floor in risk of getting stepped on (and he likes being eye level with Eren). The first big thing Arian gets is a tiny, functional tea set which he uses every day.
When under extreme emotions (good or bad), Arian can poof back into one of his more animalistic forms until he calms back down. He also often keeps mouse mannerisms, like chittering and popcorning and wanting to groom people he likes.
Summary: Eren saves a tiny mouse (or baby rat?) Arian from becoming snake food at a local pet store. He’s instantly like a nervous but enthusiastic new father, reading up on how to take care of mice and buying all the best things for him even though he has to make his paycheck stretch. Eren and Arian bond so deeply that Arian becomes a magical animal (through the power of ~love~), quickly adapting to a mindset of around 16-20 years old, which would have been his age in mouse years. He stays that way and continues to age at a human pace, giving him a prolonged lifespan.
In addition to becoming sentient (basically indistinguishable from a normal human teenager though he lacks in a lot of basic knowledge at first), Arian soon becomes able to change into a human form - though only partially at first. The first form he gets is only slightly more human, and only about twice as big as his mouse form (Anthro), and still can’t speak human language in it. But he continues to find new forms that get increasingly more human in increments, and can choose to change into any of them, including back into a normal mouse.
As soon as Eren realizes Arian is sentient, he blows all of his money on dollhouse stuff, which is the perfect size for him in his anthro form. Arian then lives with open cages and little dollhouses, coming and going as he pleases but Eren keeps adding panels to walls so Arian can get around without going on the floor in risk of getting stepped on (and he likes being eye level with Eren). The first big thing Arian gets is a tiny, functional tea set which he uses every day.
When under extreme emotions (good or bad), Arian can poof back into one of his more animalistic forms until he calms back down. He also often keeps mouse mannerisms, like chittering and popcorning and wanting to groom people he likes.