Delta

Delta is a Velociraptor that was trained along with the rest of her pack by Owen Grady.

Creation
Delta was the second Velociraptor to be created by InGen for the Raptor Research Arena.[1] She belonged to a pack consisiting of Blue, Charlie, and Echo.[2] She was created using more avian DNA, resulting in more birdlike movements and actions.[1] She and her pack were trained by Owen Grady, who inprinted on them in their birth.[2]

Isla Nublar Incident (2015)
Delta and her packmates assisted their trainer in stopping the genetic hybrid Indominus rex's rampage. After her and her packmates met the Indominus rex, Delta and the rest of the raptors turned against Owen and the others. While Claire was driving the truck, Delta and Echo were chasing behind it trying to kill Claire and the boys. Delta came from behind the vehicle and pounced on an InGen trooper. She later pursued the humans with Echo as they tried to escape in the vehicle, but she smashed into a nearby object while chasing the vehicle.

They soon gave up and went into the forest. Some time later Delta is seen inside the visitors center, having stealthily followed Claire and her nephews there and kills Hoskins. After she kills Hoskins, she continues her pursuit of Owen, Claire and the boys before being distracted by a hologram of a Dilophosaurus that was activated by Gray, but continued her pursuit after realizing it wasn't real. She is eventually met up with Blue and Echo (who surround Owen, Claire, Gray and Zach). The Indominus rex soon shows up and communicates with Blue, who then decides to turn on the Indominus. The hybrid knocks Blue into a wall, knocking her out. Delta and Echo team up and fight the Indominus. Sadly, the two are overwhelmed by the hybrid. Echo is thrown into a grill and gets engulfed in flames and Delta is tossed away by the Indominus. [2]

Barry
Barry appears to be Delta's personal trainer. He understands her behavior when she's hungry. Barry most likely had a closer relationship with her than with Owen.

Vic Hoskins
Delta seemed to take an immediate disliking to Hoskins, as shown when Hoskins was petting her; she hissed and growled aggressively and sinisterly. Barry later tells him that she only does that when she's hungry. Delta's hatred for him was fulfilled when Hoskins attempted to calm her down using Owen Grady's hand signal, it failed, and Delta bit Hoskin's arm and swiftly killed him.

Blue
Delta is assumed to be Blue's second in command, as she and Blue can be seen communicating and working together many times throughout the film, such as when Blue and Delta were chasing the van Claire Dearing was driving, or when Leon fell into the Raptor paddock and Blue and Delta were the first to corner him. When the Indominus Rex seemingly killed Blue, Delta and Echo try to avenge Blue, but they both end up losing.