Elkcestor

Regular culture

Appearance (Basic)

Additional abilities (besides Great Elk)

Elemental

Appearance

Additional abilities (besides Cultural)

Valkesia

It takes on a slightly blueish tint with globulous glowing eyes and bright coloured vine-like designs along its sides.

Level 3+ (Mobile warband): As a reaction, the elk creates an illusory elk and both move up to half its movement without causing an attack of opportunity for one opponent
Level 5+ (Berserkir): The elk goes into a frenzy and can attack each creature within 10ft once as an action (one time use)

Selkie (water)

It gains a fish-like tail instead of back legs but its face looks like a long but visibly human one. It has hooked horns.

Basic: Amphibious, 30ft swimming
Level 3+ (Siren Glow): The selkie releases a soft glow attracting the attention of all those within 30ft. All must make a DC 14 Wisdom save or be charmed (can reattempt at end of their turn) (one time use).
Level 5+ (Whirlpool): Anyone within 20ft must make a DC 16 Strength save to move. On a success they can move up to half their movement speed, on a failure they take 4d8 bludgeoning damage (one time use).

Kraveik

Its fur becomes a russet reddish tinge and strangely, it appears already bridled in painted gold leathers.

Level 3+ (Backstop): The elk provides a healing warmth within 10ft of it, regenerating 2 hit points for nearby allies at the start of each of its turns
Level 5+ (Plains rider): Anyone riding the elk becomes resistant to non-magical damage for the duration

Beelzebelk (fire)

Fire runs down its back and it stands up on its back legs. Its horns become particularly long and its fur is jet black.

Basic: Fire resistance
Level 3+ (Devil's Own): Wherever the elk walks, fire springs up behind causing 3d6 fire damage for anyone walking through. This lasts 1d3 rounds.
Level 5+ (Fire Cage): Flames blaze up around any creature within 30ft. On a failed DC 16 Dexterity save, the creature takes 2d6 fire damage. The check must be repeated at the start of that creature's turn for 1d3 rounds.

Rynsysia

The elk seems to weigh barely a feather and almost floats off the ground. It becomes paler and small scales like ice crystals gather around its eyes and mouth.

Level 3+ (Knowledge of the Ages): The elk grants one skill, weapon, language or tool proficiency to all those touching them (one choice a day)
Level 5+ (Mind of the Ancients): The elk whispers to the wind and causes two opponents of its choice within 60ft to roll a Wisdom save (DC 14) or it has to use its next turn to attack an ally or itself if none are within 10ft of the target (one time use)

Draelke (air)

This elk is thin and shorter than the others, often almost skeletal and very pale with swirling horns. When it jumps flaps of skin similar to a bat's sprouts from its sides and runs along its legs to form four great wings. It's tail is also longer and forked.

Basic: No fall damage
Level 3+ (Repel): As a reaction, the elk can grow its wings and beat them heavily causing it to take 2d8 less damage. This has 1d3 uses.
Level 5+ (Wind Cape): The elk forms a whirling vortex of air around it giving all ranged attacks disadvantage and resistance to non-magical melee damage, lasting 1d3 rounds (one time use).

Khizdus

It's fur takes on a metallic reflection and it feels hard to the touch, with strange wires running down from its head.

Level 3+ (Metalcraft): Anyone touching the elk, ally or not, will gain a +2 to AC if wearing primarily metal armour
Level 5+ (Mountain born): When the elk is hit it can use a reaction to attempt to reflect the damage (Strength DC 14). On a success the elk takes no damage, or half on a failure.

Ylkir (earth)

It grows larger than even a giant elk, brushing the tops of the trees. Its fur is torn and ragged like a rocky mountainside and appears in patchwork form tied with vines and autumnal leaves.

Basic: Stealth advantage in mountainous or forest regions
Level 3+ (Spread the grains): The elk divides itself into multiple parts (based on the patches). Its damage and health is divided by half if split in two and in quarters if split in four. Each part can make an independent action. Each part can move up to 20ft away from each other.
Level 5+ (Bring life): The elk causes up to three plants it is touching of size medium or above to become living creatures. They will mimic the type of the elk's last move (offensive, evasive, defensive) on the elk's last target. Plants take their turns directly after and deal 2d6 bludgeoning/piercing damage and have 26hp (can vary with the plant at the DM's discretion) (one time use).