Old Mister Mallard, Part 6

Old Mister Mallard has a favorite swimming hole very close to his house that he frequents several times a week. He'd tell you that he enjoys the feeling of the mud at the bottom on his feet. In actuality, the depths of this particular pond happen to be a spatially-locked time portal to the precambrian era, and the "mud" he believes himself to be sinking his webbed limbs into is a gargantuan, prehistoric amoeba. Luckily for Old Mister Mallard, this amoeba is by no means metabolically enabled to eat duck, though it's uncannily enabled to be annoyed by the farmer's kicking and poking.