Remember Action Masters? The Transformers who can't transform that ended Transformers forever and ever? (transformers was honestly pretty dead before then) Well, Action Master Soundwave came with a little transformable partner named Wingthing, and he was an orange and black bat. A few years ago, Ratbat was redecoed in orange and black as an updated Wingthing, and this new Masterpiece Wingthing updates that toy again. (Surprise, it's Masterpiece Ratbat in orange and black!)
Masterpiece Ratbat is one of the best Masterpiece cassettes, probably coming in a close second to MP Laserbeak/Buzzsaw. Ravage is kinda okayish and Frenzy/Rumble is comparatively boring because it's just a boxy dude, but Ratbat is pretty darn good! And so, you know, Wingthing benefits by also being MP Ratbat, but in different colors. Somehow this mini-cassette-shaped thing becomes this three-dimensional robobat -- essentially, everything that's not wings triples up on itself to create a block of torso. That includes what used to be removeable accessories on the original toy; like MP Buzzsaw/Laserbeak, those parts are now integrated into the transformation. And it's pretty rad!
There are little grooves underneath Wingthing's feet so that you can slot him onto corresponding grooves on MP Soundwave's shoulder or forearm.
If I had a complaint, it's that his head isn't black, like the original Action Master partner. I assume the original Ratbat redeco had an orange head instead of black because of how the plastic layouts work, but there's nothing stopping painting MP Wingthing's head black along with his black-painted torso. I guess it was decided to mirror the Ratbat redeco version of Wingthing rather than the original Action Master toy. Iunno.