No dog here - animal forbidden!
for pentax K mount? not many choices:
Both K50/1.2 and A50/1.2 are superb.
I don't have the cosina, but didn't like the bokeh from last time i saw.
Yashinon Tomioka 55/1.2 is nice too, different rending, m42.
Olympus OM 55/1.2 also superb, no mc, but rending so nice. Easy convert to K mount.
Canon fd 55/1.2 and 85/1.2 must use on film bodies or mirrorless like sony nex.
My choice? Tomioka 55/1.2 and/or Olympus OM 55/1.2 in 50-55 range. and 85/1.2 for portraits at f1.2
Olympus OM 55/1.2:
Tomioka 55/1.2:
Pentax K50/1.2:
Canon fd 55/1.2:
Canon fd 85/1.2: