Ghouls - ?, morytania, cannon, c longs, purely for the music track
Abberant spectre - 443, dual xbows, slay tower during a slayer task
Mummy - 1789, wand + orb, dt pyramid
Goblin - 430, wand + orb, cannon, a cave near fishing guild
Skeleton - 8,020, wand + orb, ice barrage, Lumb catacombs
Giant - 5683 dry (unfinished), wand + orb, cannon, Edge dung
Well, although I'm not going for trimmed comp, I've been hunting some champ scrolls, it was fun at start and mummies was super afk but at some point it started to be really boring and all those giants were just enough for me. Maybe I will finish this but not in the near future.
If you are interested, here's the table with probabilities:
http://puu.sh/83UeO.png
It is based on the probability of the champ's scroll drop, which is 1/5000. I don't know if there are another factors, like kills in a row, combat level of a monster, other drops (rdt...). Note, that the chance is never 100%, even after lets say 1m kills. The equation is:
P = (1-pow((1-p), n)) * 100 [%], where n means ammount of kills and p is probability of the drop (in this case 1/5000)