I'm 39 years old human (some kind of pseudointelligent protein lifeform) from Earth, 3rd planet from star called "Sun" and located somewhere in a pity galaxy called "Milky Way" (part of Virgo supercluster). My planet have 1 moon orbiting around. Earth's mean radius is 6,371.0 km. Atmosphere consists of nitrogene and oxygene so you need to wear gas mask probably.
I like cats (small mammal pets), quantum physics (some kind of human science), roofs (top of human buildings), λ-calculus (funniest thing in Universe), bismuth crystals (shaped like my brain), complex base numerical systems (especially quater-imaginary base) and mountains (large landforms).
You can send me any uncommon card containing important information about your planet. I like strange and unexplainable things. You can draw something on postcard instead of writing any phrases. If you cannot write, you can put your tentacle into paint and leave some tentacleprints for me (but please do not use your gonad tentacles).