Necessity might be the mother of invention, but overpriced metal model box sets are the mother of conversion. Here are the Panzerknackers, in all their Bloo-Flame glory.
Tankbustas were one of my favorite unit in 4e. While they might not be the strongest unit for 5e, they're still fun to chuck on the table. These were made up of regular Boyz plastics, and a fair bit of plastic card and tubing. I had a fantastic time converting these boys up, especially the weapons. I wanted as many variations of rokkit launcher as possible, from the standard shoulder mount, to a large bore grenade launcher, to small, hand held rokkit pistols.
They all sport a masked helmet of some sort, a style cue taken directly from the 4e codex art for the unit. I liked the flavor, as it gave them a more predatory feel. I can just picture a small group of these guys hunkered down in some rubble, peering through vision slits, waiting for their target to trundle into range.
Also in the pipeline for this unit are some bomb squigs and a boy with a Tankhamma. I simply can not say no to a weapon so undeniably brutal. I've gone with a slightly different approach though, as the simple "Rokkit on a Stick" seemed a bit too disposable. I went with an actual hammer design, that uses the rokkit as an impact charge to bring the hurt.
Essentially, a rokkit-powered tank tenderizer. He still needs a bit of smoothing before primer and paint, but trust that he'll receive the full Bloo-Flame treatment like the rest of the lads.