Description
Brass dragon wyrmlings love to talk, and will talk to anyone whether the other being talks back or not. If no one stops to talk to the wyrmling, it will talk to itself. Talking and listening to your wyrmling is one way to ensure that the wyrmling will bond to you, as brass dragons are very social creatures.
Traits
Keen Senses
Your Dragon counts as one size larger when determining its carrying capacity and the weight it can push, drag, or lift, and for the purpose of carrying a rider. Your dragon counts as large for all purposes that would grant it additional benefits, such as the Mounted Combatant feat. As such you can also ride your dragon as a mount, even if your size is Medium.
Glide
Your dragon is unable to fly until 6th level, however when falling it can can use its reaction to slow its descent, as if under the effects of a feather fall spell. It can move one foot horizontally for each foot that it falls this way. If you are falling as well within 60 feet of your dragon, then it can move towards you and immediately cause you to be mounted as part of an object interaction.
Elemental Bite (PB/Day)
When your dragon hits a target with its bite, it can deal extra damage of its associated damage type, or regain hit points. The amount of either option is equal to 1d6 + your warlock level.
Talkative Dragon
Your brass dragon can cast the speak with animals and comprehend languages spells at will. While your dragon is under the effect of the comprehend languages spell, creatures who speak at least one language can understand the literal meaning of your dragon's words, but your dragon has disadvantage on all Charisma checks against creatures that do not share a known language with your dragon. Additionally, you and your dragon gain proficiency in the Persuasion skill (+2 plus PB in its stat block).
When you use your action or bonus action to command your brass dragon to take the Hide action, it can burrow itself just below the surface into non-rock earth, after which it gains a burrow speed of 15 feet through non-rock earth until it reemerges for free while near the surface. Its vision, breathing, and hearing is unhindered, unless it burrows deeper than 15 feet. It cannot interact with the surface while burrowed, nor can it burrow this way while carrying a rider. While burrowed, your dragon has total cover, and creatures suffer a -5 penalty to their ability checks to find it.
Actions
Bite
Melee Weapon Attack: +3 +PB to hit, reach 5 ft., one target. Hit: 7 (1d8 + 1 plus PB) piercing damage.