Several years back, I split a Sanctus Reach: Stormclaw box set with a Space Wolves player and got started on the Killa Kans. I immediately took a liking to these armored Ork walkers and started building my own shortly after from junk and spare parts. It seemed a proppa Orky way to go.
Looking back, I remain reasonably pleased with the paint job on these first models. It's a passable tabletop quality, and that's good enough for me, I think.
I also traded for a bunch of spare parts and collected a lot of suitable scrap to try making my own, as noted above. The first on the left here was far too small, but the other two seem close enough in size to satisfy me. The tiny one will still probably see use, but it is also very fragile. Maybe I can re-use some of the components for something else if it breaks too often.
Trading also got me 2-1/2 old metal Killa Kan models. These are goofier than the new plastic kits. I removed the too-small 40mm bases, stripped the paint with acetone, and tried building a replacement front body panel and weapon to complete the third. I am not entirely satisfied with the results, but this may be good enough. I should prime these and then rethink it if I still don't like it.
Lastly, here are some Kans that may be a bit too large, but these are too fun not to use anyway. The blue one uses a sphere from a vending machine dispenser, about the size of a ping-pong ball. The white model is a primed conversion of a poor-quality R2-D2 action figure. Once it's painted up, I may go over the build process in detail. And just for reference, one of the official models from the first picture is included, too.
Later on, perhaps I will show off some Deff Dreads. These larger cousins of Killa Kans also have neat official models and opportunities to build from scratch. The large kans above are still too small to be mistaken for Dreads, so I doubt anyone would object to their use in a friendly game. Some may even have enough Games Workshop parts to be considered tournament-legal, but I don't care for the hyper-competitive brand snobs who congregate there.