Yup. It's the one he carries on his back when he was Vile-MKII (But never uses it aside from the MMX3 manga)

For full Collab credits, as well as links to the artists' pages and links to the individual works from this Collab, please check out the linked document. The document also contains a link to the Discord server, in case you wish to participate in future events: docs.google.com/document/d/1...

Collab link:
www.newgrounds.com/art/view/dio...