The barrel would grant cover, so you're fine there. But the bluff could use some work. Better to point behind the enemy and scream, "Oh my god! That baby is eating a kitten!" And then you jump in the barrel when people turn around to see the feral infant.
Wæs se grimma gæst Grendel haten,mære mearcstapa, se þe moras heold
Yeah it really isn't a very plausible lie. Could someone like the Chinese monkey god of trickery make it work? Probably. Henrik? Maybe against an animal or giant ant or something. Or a baby who hadn't yet tackled object permanence.
These beings from another dimension might not have object permanence. Maybe things wink in and out of existence seemingly at random.
You should look for Monty Python's 'How to Hide' on YouTube. I can't link to it from work, but not only is it good times, it is probably relevant.
I should have tried to convince them that letting me go would show fear and work to their advantage.