I changed it a bit and commented what I changed.
Simba Code:
procedure kill;
begin
if P07_FindObjCustom(x, y, ['ttack', 'oblin'], [3511438, 2519700, 11908543, 5207393, 3760540, 1863248, 8097434,3357762], 5) then
begin //You forgot to put a begin/end, so it only executed the next line
WriteLn('Found Goblin')//Will print this to debug if it finds the goblin
MMouse(x, y, 0, 0); //Changed to MMouse
ClickMouse2(False); //And ClickMouse2
ChooseOption('ake');
repeat
Wait(RandomRange(3500,2500));
Until not IsUpText('oblin')
end else //I added this to match the begin I added, you could also use end; if you don't want the debug message
WriteLn('Could not find Goblin'); //Will print this to debug if it doesn't find the goblin
end;