I think we may need more context on most of these to answer well. I'm going to leave the answer space to native speakers and answer what I can while on the subway this morning. I think 해달라고 is reported speech grammar on a noun. More completely, it might be 해달라고 했다. (He/she/I/other said it is a sea otter). Or maybe 해달라고 생각해요. (I think it's a sea otter) and several other versins expressing that someone said, answered, heard, or thought that. The 라고 marks the end of the reported speech or thought, but there are several of these depending on what it is reporting. In this case, it is a noun, so (이) 라고 is used. For a noun, a direct non-question quote in quotation marks, or imperative (command), 라고 is used. For a statement (ㄴ/는) 다고 is used. For a suggestion of something we the speaker will do together with the person spoken to 자고 is used. For a question, 냐고 is used. I suggest searching google or bing for -라고 grammar, and you will likely find pages that explain more on reported speech than I can here. And I apologize, but the next stop is mine, so that's all my time. I hope I didn't make too many typos, and that this is helpful.