Even Tankaa can find the the Trenchcoat of Incongruity and Dark Shades of Incompetence in his size. It still looks indescribably cool, even though it makes him even more obvious than a naked pliosaur or pliosaur in a boilersuit could ever be. Even if he showed up during an era when a trenchcoat/duster and fedora made sense, it still makes him look like a small leather-covered mountain with a stubby tail and lots of teeth.
I don't think Tankaa will be wearing a proper suit and tie underneath the biker's duster if this one gets defictionalized. Maybe just a boilersuit similar to what Ori will soon be wearing, since they're an order of magnitude cheaper. (Considering Ori's barrel-like physique, he probably could get away with wearing things sized for Tankaa with the various adjustments taken in.)
Artwork, Tankaa (c) of me
"Trenchcoat of Incongruity and Shades of Incompetence" (c) of Howard Tayler
Kaijusaur Basic Design by me and Borusa