Taskmaster Dragon 

A hellish dragon with 4 arms, bipedal. It dons whips in two of those arms. It would be a Fire Dark Element. It would likely be primarily red maybe with Horns and having brimstone like accents.

Stage Descriptions: 

Egg - You feel compelled to take this egg.

Hatch - This mischievous hatch already has you doing it's bidding.

Hatchling - Now older and stronger it has started to organise other hatchlings to do it's bidding.

Adult - Using it's Command and Intimidating presence this dragon forces other to work harder.

I'd propose a special ability for this dragon that would reduce the wait timer for a training session by 6h. Effectively adding an extra training session.

This ability could give those who need that last push to achieve the personalities they are aiming for. 

It isn't necessary but as for it's lore, as Taskmaster the ability fits in.

The artwork below is a very rough idea and I have listed the stage and some colouration ideas for each. It's main lore will be below all the art.

Thanks in advance for having a look!

Adult Form.

It's Main Body colour would be a crimson colour with Black ashy accent colours. It's holding a pronged Whip. It's tail is barbed and spined, as are it's wings. The wing membrane would be a translucent Grey.

Hatchling (juvenile stage)

The colour scheme stays the same as the adult. The main difference being that it's legs are only 2 sections and not 3. 

Hatch 

Same as above but only one leg section, hence is pose of it being sat.

Egg would be Crimson like the main body colour wrapped in dark silver chains, with the black horns poking through.

Story

The Taskmaster Dragon is usually despised by others. From it's early stages it usually tries to take charge and position itself as a leader. Later on it abuses this position and standing in order to extract the most out of other dragons. Although it's behaviour is exploitative, it is actually quite valuable. It pressures other Dragons to work and train harder than they would with tamers, more so on dragons that it finds in the Shelter. 

This dragon believe that training and hard work is the best way to become more powerful and so pushes on its idealogy onto others.

Amongst other dragons, it is actually Angra who values the Taskmasters the most. With Angra's special powers combined with a Taskmaster, a combatant Dragon could become Unstoppable!

However this means such dragons grew some disdain. Karura, Mithra and Taygeta all Value a Taskmaster, but even for them sometimes it can be too overbearing.

As time has passed the Taskmaster has become less a brute used to punish, but more of a teacher, to push dragons to achieve their best. As such they seldom find themselves without willing subjects to be subjected to their ways.