Mer Creature are Aquatic Mammals from the Future from Primeval They are seen in 2.4, 2.6 and 2.7 of Primeval.
In Episode 2.4, Several Mer Creatures came threw an Anomaly from the future to the present at the beginning a boy named Lucien Hope was kidnapped by one of the creatures from a drain they tried to find him but they could not so they searched the canal at night and they were attacked by a Future Shark that was Mistaken for the creature they killed the shark and took it back to the Anomaly Research Centre but they found out it was not the shark and went searching again then they went back searching in the Canal again but this time the creature took Abby Maitland when Nick Cutter tried to draw the Mer creature out with using a recording of there song. The Mer creature took Abby and Lucien and keep them in a flooded tank. when Cutter, Connor Temple and Stephen Hart discovered the Mer's lair in the abandoned warehouse Lucien but one of the creatures took Abby Maitland then Abby knocked out the creature to stay alive when Connor found Abby the Mer Queen Appeared and knocked Connor into the water Abby fort he died then Lucien and Cutter where attacked by a Mer Creature and Lucien threw a rock at its head killing it instantly then another one attacked Cutter throwing him in a Flooded tank then Stephen Hart controlled a drone up there and distracted the creature and was eaten by it then Stephen came and shot the all six of the remaining Mer Creatures dead then Connor followed the Mer Queen threw the Anomaly and found Abby being attacked by a Mer Creature then Connor killed it by throwing a rock at its head killing it instantly then Connor tried to pull Abby up and confessing his love for her then just about when Abby was about to fall and accidentally take Connor with her then Nick came and pulled them both up and then Cutter and Stephen shot the Mer Queen dead.
In Episode 2.6 When Cutter woke up from being knocked out by one of Oliver Leek's bodyguards and saw Two Mer Creatures.
In Episode 2.7 when Oliver Leek accidentally downloaded Connor Temple's virus all the Creatures including the two Mer Creatures then when they sounded the alarm to get the all the creatures in the same room so they could destroy each other then when Stephen Hart sacrificed him self to save the world The Mer Creatures where one of the other creatures to kill him and then the Mer Creatures where destroyed by the other Creatures and each other.
- Oliver Leek's Creatures where Mer Creatures, Silurian Scorpion's, Future Predators's, Smilodon, Raptor's, Arthopleura, Coelurosauravus, Scutosaurus.