Describing a person who is good company.
An entertainer, or class act. (Usually a male)
Someone who is likable, and amusing at the same time.
If there is Someone you see every so often, and just get either happy or excited, or if your mood changes positively, you describe that Someone as being a Yerm. Or simply call them Yerm.
Prefixes describing the person like small, big, tiny etc. can be used. For example, Big Yerm.