Enemy Hero: Mr. GobGoblob X
Enemy Level: 6,000
Hero Stats: 2,500,000 HP / 90,000 Att / 15,000 Def
Aptitude: 0 / 0 / 0
Boss Spells: Special Attack
Info: The Master Assasin(Random Instant Kill)
Enemy Units: Shadow Goblin (Ex)- True_Fire, Pop 30, Cost 1.
BP Cost: 3,000 BP.
Exp Reward: 50,000 Exp.
Item Reward: Assasin Knife
Strategy: Despite of his instant kill skill you can beat him pretty easily just keep spamming Pegasus Knights. This is a time eater boss so if you want a certain win equip 1 Doping Pill and 1 Dragon Egg, and attack items; +thunder is preferable. (If you are at a higher level, below level 500 Dimes will certainly give you more attack power.) Just keep spaming them with rage and eventually he will die, it certainly does take awhile though.
Another strategy I wouldn't really recommend but can work (at much higher levels) is this:
Another strategy is to send fast water units (e.g. Valkyries) as soon as the battle starts to keep his goblins away from hero. Then spawn Pegasus Knights to slowly start pushing them towards their spawn point. Spawn Valkyries occasionally to keep goblins out. The key to success is to carefully Ice Blast him from the distance. Don't let him touch you, hence his attacks are deadly. Slowly Pegasi will build up making a repellent barrier. Just keep Ice Blasting him. Overall process can be quite time-consuming so might wanna equip Time + item like Khronos Shield or a Time+ consumable( I would recommend Invisibility cloaks as they give Thunder/Mana/Time + M)