Combinations of other elements are not yet known. Walkthrough for The Doctor in Little Alchemy

1. earth + fire = lava
2. water + fire = steam
3. Earth + water = water + earth =
4. air + fire = energy
5. Air + Water = Rain
6. Earth + rain = plant
7. fire + mud = brick
8. air + lavas = stone
9. steam + air = cloud
10. Brick + wall = brick
11. Stone + air = sand
12. clouds + air = sky
13. glass made of sand + fire
14. mud + plant = swamp
15. Wall + house = wall
16. energy + swamp = life
17. Stone + sky = moon
18. earth + life = human
19. Glass + Sand = Time
20. human + rain = sickness
21. Sky + moon = night.
22. night + sky = star
23. House + sickness = hospital
24. Sky + Star = Space
25. hospital + human = doctor
26. time + space + time = Tardis
27. Doctor + Tardis = The Doctor