If not picking own stat adjustments,you gain a +2 to Dexterity and a +1 to Wisdom or vice versa.

You can speak Common, KayNine , and one other language of your choice

You have 40 feet of darkvision

You can make unarmed melee strikes using your compact but sharpened fangs as a natural melee weapon and can also use this as a bonus action, you are proficient with this bite attack that deals 1d6+strength piercing damage. Additionally, you have finely tuned senses beyond your sight including your hearing and smell and gain advantage in Perception checks with one of those two senses

Resistance to Cold Damage(Thick Coat) or movement becomes 35 feet(Short Coat)

A number of times equal to your profiency modifier per long rest, your presence alone can pacify the fears of your allies and either remove the Fear condition from an ally within 30 feet or give advantage to an allys roll within 30 feet as a bonus action. You also gain proficiency in two skills of your choice.

Small Dog: Fury of the Small. When you damage a creature with an attack or a spell and the creature's size is larger than yours, you can cause the attack or spell to deal extra damage to the creature. The extra damage equals your level. Once you use this trait, you can't use it again until you finish a short or long rest.

Medium Dog: You gain proficiency between two items comprising either a Tool Set or Games Set

Big Dog: Powerful Build:You count as one size larger when determining your carrying capacity and the weight you can push, drag, or lift.