Another easy mod.
Only cut and past of an Ultimate Skewb.

way cool! the curves are sweet.

And it does NOT change its shape. Very cool.

I like it! It looks well-made! Looks like a simple yet creative modification!

Wow! That's great. I love the fact that it doesn't shapeshift.

Nice! However 2 points of concern...

(1) Reuleaux Tetrahedron is a well defined shape. And I fail to see the relationship between this shape and a Reuleaux Tetrahedron. The surfaces don't appear to be spherical. Is this an actually transformation applied to a Reuleaux Tetrahedron or should it be called a Curvy Pillowed Tetrahedron Shewb?

(2) The pictures are very deceiving. The last 2 pictures made me think I was looking at the Peanut shape presented here but with sharp corners. However the first pic clearly isn't so I at first thought this did shape shift. Once I realized this was a Tetrahedron and therefore had 4 sides and not 6 I now see how I was deceived by the pictures. Would it be possible to post a picture which shows at last the entire surface of one side?

Carl

Thanks to all for your comments.

Carl. you are right. I don't call it Reuleaux. Here comes the picture you want: