In solo uldum i have a 7/7 c’thun in my deck (added from bazaar with +1+1) . I have capture flag passive for +1/+1. At the start of the game there is an animation showing C’thun is 7/7. When i draw the c’thun it is 8/8 then after a couple of seconds turns to a 9/9. There seems to be an extra +1/+1 from somewhere