Yes, you will need a multi engine rating to fly the CRI-CRI (cricket in french).
It is not a derivative of the BD-5.
The BD-5 was a US design and used in one of the Bond movies;
Prop version;
Jet version:
Here is a website with a lot of info on these little rockets;
http://www.aerospaceweb.org/question/planes/q0256.shtml