Well, rhino is the name of an optional plugin that runs with WorldEdit. I don't know if this is the same rhino or if there is a rhino mod out there that I have no idea about.
http://gyazo.com/d50f18c237fb75fe4067da176fea314c .
I am not a pro on mods so I am unable to help you with that, but just curious is this running on a server or on a client. The last time I checked, plugins such as WorldEdit are only usable on servers, and even then they are buggy when they are used along side mods. If this is run on a server, then I might be wrong. The mod that is most similar to WorldEdit is Single Player Commands in case you were wondering.
