Non-German speaker looking for part or full time work.

In general it is almost impossible to do much without knowing the language at least on an elementary level. The only option in most places might be stocking shelves in a supermarket, flipping burgers at MsDonalds or doing gardening work etc; hard manual labor in bad conditions for little money. Even for these jobs a person with some German would probably be preferred so that the boss can communicate with you. 

The exceptions are usually in high level jobs say in specialized fields of IT, Engineering or natural sciences - and then usually in research or academic positions rather than where one has to interact with customers of some sort. Assuming one has the legal licenses needed to offer services as a say a psychologist, one could theoretically market their services to English speakers. Such a thing is probably possible in large cities like Berlin, Hamburg or Munich. Smaller communities are unlikely to have a large enough community of English speakers to support this. There are of course exceptions to almost every rule in life so maybe you will be lucky but you should go into the situation with eyes wide open.