DnD Homebrew: Hellhound playable species

Your are a fiend.

Your Strength score increases by 2.

(I have no idea tbh, somewhere between drawves and elves maybe?)

Your size is medium.

Your walking speed is 30 feet. This increases to 45 feet in beast form.

You can speak, read and write Common and Infernal. In beast form you cannot speak or write, but can understand all languages you know. However, while in beast form, you gain the ability to speak with animals as though you were using the "Speak with Animals" spell.

When leaving the nine hells, you took on a fixed humanoid disguise (which still resembles an anthro furry, similar to a Tabaxi), but you can turn to your original beast form at will.

Thanks to your infernal heritage, you have superior vision in dark and dim conditions. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of gray.

You have proficiency in the Perception skill.

You have resistance to fire damage.

You can use your action to exhale fire in a 15-foot cone.
When you do so, each creature in the area must make a DEX saving throw. The DC for this saving throw equals 8 + PB + CON. A creature takes 2d6 damage on a failed save, and half as much damage on a successful one. The damage increases to 3d6 at 6th level, 4d6 at 11th level, and 5d6 at 16th level.
After you use your breath weapon, you can’t use it again until you complete a short or long rest.

You can transform to your original beastly hound form (and back) at will. The transformation takes 1 minute to complete in each direction.
In your beast form, you gain natural armor, a bite attack, and the ability to speak with other animals.
Like a wildshaping druid, you choose whether your equipment falls to the ground in your space, merges into your new form, or is worn by it. Worn equipment functions as normal, but the DM decides whether it is practical for your beast form to wear a piece of equipment. Your equipment doesn’t change size or shape to match your beast form, and any equipment that your beast form can’t wear must either fall to the ground or merge with it. Equipment that merges with your beast form has no effect until you leave the beast form. You also cannot use items or mechanisms, unless a simple push or scratch of a paw is sufficient.
Also similar to a druids wildshape, your beast form limits your ability to cast spells. You cannot cast new spells, but retain concentration on any spells you have already cast, and are able to use actions of ongoing spells, such as those of "Witch Bolt" or "Call Lightning".

While in your beast form, and you aren’t wearing armor, you have an AC equal to 15 + DEX.

While in your beast form, you can use your bite as unarmed strikes. These attacks deal 1d6 + STR piercing damage plus 1d4 fire damage, instead of the bludgeoning damage usual for an unarmed strike.