It all very much depends on the quality of the drawing though. From the information and sketching above it seems fairly clear to me that this is a crustacean at least. I’m not much good with crustaceans, so I don’t know if it is possible to confirm it as an Amphipod, but I kind of doubt it would be possible to get it below family, so it wouldn’t get research grade anyway.
I once came across a superb field sketch of Volucella pellucens - so good I could even tell it was female (and that’s a species where the sex can catch people out!). Person said they didn’t have a camera, but they did have a pencil and paper, so they outlined it while the animal was there and remembered the colours to fill in later. Anyway, if it’s identifiable we should identify it to the level to which it is identifiable. If it’s such a good sketch that you can get it to subfamily or better it will become RG, if not then not.