D&D 5E Let's talk about monster design philosophies, by way of examples.

[Charlaquin]

The 5E MM goblin can be viewed here at 5esrd.com and it's pretty basic: it has a melee attack, a ranged attack, and an ability to take the Disengage action as a bonus action. Since it has no other possible bonus action available to it, the goblin should never be standing still. Of course, it does not have any extra movement, so its movement won't amount to much unless the GM builds the encounter to reward mobility. This goblin is our baseline.

The LevelUp goblin can be found at A5Etol.com (which as of this writing is not loading for me so i can't link it.) The LevelUp goblin is nearly identical to the MM goblin except it can choose between Hide or Disengage as a bonus action -- and the goblin gets a bonus to Stealth rolls. This ostensibly makes the goblin more versatile, but it should be notes that again without additional movement even this requires the GM make sure the environment is set up to take special advantage of the ability. Moreover, the LevelUp goblin comes with an explicit number of variants that use different equipment and tactics (but retaining the Nimble Escape bonus action).

Actually the 5e MM goblin can hide as a bonus action too. The srd stat block you linked to even says so.

 

[Reynard]

Actually the 5e MM goblin can hide as a bonus action too. The srd stat block you linked to even says so.

That is so weird that my eyes glossed over it. I was actually using a pdf of the MM and Hid is at the end of the line so I think I simply wasn't reading carefully enough.

 

[Reynard]

I put together a draft of a Tarrasque level threat for publication. If folks are interested I'll share the stat block here and we can talk about it from a design perspective.