Sizes: You can roughly assume by the didi chart in the ref section, basically the guy was 6' tall~
Lifespan: Ageless, although if they stay in physical form for a SOLID 12-15 years, they die naturally of old age.
Diet: Do not need to eat unless in physical form, as they are made of energy alone and feed off of energy around them from all sources, but generally not so much that it causes problems to living things.
Habitat: They can live anywhere in the universe, except for the vacuum of space, surface of the sun, bottom of the ocean, etc. , but in terms of mating areas, they prefer locations of great spiritual and ancient energies, such as temples, shrines, ruins, tombs, ancient cities, pyramids, and so forth. This energy is required to create larger amounts of offspring, and healthier offspring, in a litter.
Lifestyle: Normally live in family groups or travel solo, although packs do occasionally form, and even then they're fairly small and aren't ridged in structure. Didis are naturally naughty, curious, adventurous, fun-loving, carefree, and even imp-like for the most part. Of course, this depends on the individual~
Body: Can phase between being "out of existence" (AKA, in their own dimension) and completely physical. They prefer being half-phased, in which they are extremely light, have no defined paws, claws, etc, and have the ability to "float" when leaping from place to place. They can also de-materialize into a misty or heavy fog that corresponds with their base fur color. Their markings glow when it's dark enough. Except for average-sized, somewhat dull teeth and dull claws in physical form, they have no natural weapons besides their cunning little brains. Their blood is a clearish version of their marking color; In bicolors, it corresponds with the eyes.
Hazards/Enemies: Dokis (The species opposite to the didi) are the didi's only natural enemy that can harm them in any form. They frequently fight over nesting areas, although the dokis are more inclined to stick around churches, castles, graveyards, and battlegrounds for theirs. Other than that, it depends upon the form they're in. In psychical form, anything that can hurt an animal can hurt them or kill a didi. While half-phased, high amounts of heat, electricity, contact with plasma, near absolute 0 temperatures, and the vacuum of space can kill them. Only dokis can kill them when fully phased-out, as they come from the same plane of existence.
Special Notes: Didis cannot carry objects with them if they don't maintain a physical or half-phased form. If they teleport while holdings something, it will simply drop to the ground. This doesn't stop them from storing their items in a concentrated spot around a "nesting site" for later retrieval. Also, even though food is not needed, while half-phased or phased in, they can still eat it as a treat.