My first army was ultramarines, and I always enjoyed converting and modifying the figures to get something different to what the stock pieces give you.
Orks take this to a new level, and since I started them I loved converting, bit-mashing and scratch building, I suffer from building too much and painting too little, so at some point I need to start using a brush instead of superglue on the boyz.
Recently I got the chance to make some meganobs and characters, as well as flash glitz and some vehicles.
Megaboss:
Necromunda ambot with all the pieces of the world to make it into a good boss for my army, second only to ghazghkull.
Meks
Mostly made from necromunda ambots


Wierdboy
Builded from random bits


Meganobs:
Those are a mixture of
AoS Orruk brutes, actual meganobs, noobs and random pieces.
Flash glitzs
Not too fancy, but thanks to this the bits of a single box I got a bunch of pieces for the rest of the conversions.

Ork Koptars
Builded from scratch with plasticard and bits.

