[If Eren's honest with himself, there are a lot of things he enjoys about his wolf form, but most of them are embarrassing to own up to, so he maintains that he intends for the animal transformation to be something he can use in combat - that's why he likes to practice! No other reasons to see here!
[With this explanation, Captain Levi agreed to help with some training. Maybe the Captain isn't all that experienced with using dogs as weapons, but that's not the point. Eren trusts that he'll give him something valuable to walk away with.
[So, he arrives at his door, already in his wolf form. Did he need to run all the way there on four legs instead of simply transforming after he and the Captain exchanged greetings? Nonsense. He sits down outside the cottage's front door and howls.]
action; puppy antics! lmk if this works
[With this explanation, Captain Levi agreed to help with some training. Maybe the Captain isn't all that experienced with using dogs as weapons, but that's not the point. Eren trusts that he'll give him something valuable to walk away with.
[So, he arrives at his door, already in his wolf form. Did he need to run all the way there on four legs instead of simply transforming after he and the Captain exchanged greetings? Nonsense. He sits down outside the cottage's front door and howls.]