I heard on the news that zombies destroyed Seoul" "No they didn't" "yeah they did, they killed everybody in less than a minute." "But they didn't throw grenades." "Oh.
How to beat Doom Frog with Scout: You should be level 40 and, if you got lucky, a weapon that deals about 150 minimum damage. Get Cheap Shot and Kidney Punch (optionally Evasion and Sline And Dice). Fight him and activate the latter two abilities, if acquired, then use Kidney Punch. Use Attack twice and then Cheap Shot, one round before Kidney Punch expires. Continue using Attack until Kidney Punch cools down. This will give you 6 hits and he will have 1 chance at Doom, which you can dodge or parry anyways, even more effectively with Evasion and (I would assume) Slice And Dice. The luck factor is of lesser need in this way.