My fantasy world of Algennon has several “Pudding” class monsters-(one of which is the Peasouper) -slimy slug creatures with natural weapons. One type is the Licorice Pudding. This monster has tentacles all all over its body, and these tentacles lay flat for the most part. But when anything gets too close, the Pudding raises its tentacles and shocks the poor, unsuspecting creature to death. It then devours the charred remains. I’m wondering, can this creature exist, based on Earth’s creature-design standards?
This monster combines traits from several real animals. It is more believable than the peasouper.
Electric shock superpowers have already evolved in the electric eel
Your pudding shocks things the same way. Its shock powers have the same drawbacks as the electric eel. Namely it runs out of juice after one shock.
Like the crab shown below, the pudding is camoflagued by the plants that grows on top of it.
Since the pudding is squishy the plants can extend their roots inside the pudding's bodies. When flattened with the tentacles retracted inside the body like a snails' the pudding looks like any old clump of moss.