jelly fish are animals the leave in the deep ocean so the dog will die few metters down the suface before he gets to the jelly fish, but imagen that he gets to it and the jelly fish attacks him in water, i am not that sure that he can kill him but yes hert him very badly. now if the jellyfish attacks out of the water his attack wodent be so powerfull and the dog would probably own him.
YES
It depends on the species of jellyfish. The irukandji jellyfish has the potential to kill a person in 2 minutes.
No. A sea anemone and a jellyfish would not meet. If they did meet, the jellyfish would sting the sea anemone and kill it.
No.
Yes a lion mane jellyfish can kill octopus. Because the octopus can not take the rage and power that the jellyfish is providing.
Yes.
No they are not
great question, yes a portuguese man-of-war can kill a jellyfish.
No, unless there is a large group of jellyfish.
kill
NO
For food.
A large box jellyfish or a man of war jellyfish could if it had very long tentacles.