Serum is the 16th episode of season 4.5
Leo drinks a bottle that was on the lab desk and he drinks it. Which turns him into a ravenous beast.
It all starts when Leo see's a bottle on the lab desk. He picks it up and Davenport snatches it from him, telling him its not a bottle of grape juice. It's a chemical serum. Leo says that he still wants to drink it and Davenport smacks Leo in the face. Everyone else starts to laugh. In the living room, it shows Tasha cleaning around the house, and Eddie hits her with a dodge ball. Tasha then takes the dodge ball and throws it at Eddie, breaking him in the process. Davenport comes back up to see Eddie broken into pieces. He then says "Tasha, I'm going to kill you!" At the lab, Leo see's the bottle of serum and no one else was in the lab, so he takes the bottle and he starts drinking it. Nothing happens at first, but he starts to feel weird and he turns into a ravenous beast. Everyone else is hanging out in the living room and the elevator doors get busted. Leo(a.k.a Serum monster) starts destroying the house. Marcus shoots a laser sphere at him but it bouces back and hits him. Leo then aims at Tasha and Davenports moves out of the way and Leo sprays Tasha with green fluid, implying that Davenport wanted to get revenge. Bree superspeeds around Leo to make him dizzy while Donald fixes Eddie. Leo grabs Bree and launches her right across the living room. Chase and Adam try using martial arts but obviously, that didn't work either. Zax and Mark make a surprise entrance. Zax electrocutes Leo and Mark burns him with his fire. Eddie starts to work again and Bree tells him to freeze him with the coolage system. Leo freezes and Mark burns it out and at that exact time, Davenport uses his Extraction invention to take out all the serum and Leo returns to normal. Adam says that Leo is fine and he "accidentaly" hits Leo with a plasma grenade. They all laugh and they help Leo up. At the end, Donald forgives Tasha for breaking Eddie, then she ask's him if she can be his lab assistant and he says no and he pushes Tasha into the couch.
Billy Unger as Chase Davenport
Spencer Boldman as Adam Davenport
Kelli Berglund as Bree Davenport
Tyrel Jackson Williams as Leo Dooley/Serum Monster
Hal Sparks as Donald Davenport
Zendaya as Sara Davenport
TBA as Dilli Davenport
G. Hannelius as Elena Davenport
Kyle Massey as Mark
Angel Parker as Tasha Davenport
Rahart Adams as Zax Knight