Aggressive is the fourth episode in Ben 10:Ultimate Omnitrix.
Ben Tennyson as Benmummy, Aguas and Tempeter were fighting Bio-bots, henchmen of Vilgax. The Bio-bots were difficult to fight. However, an alien smashed the Biobots. Ben transformed back and snatched the alien and escaped. Aguas and Tempeter followed them. The alien revealed that his name is K'arat. The alien revealed that he is capable of magic. He opened a random book and found some spells. He shouted out the words "Imimicus Agonzethai" which the energy blast reflected to the mirror and hit Gwen. Gwen asked Kevin if the Transmitter was working. Kevin replied harshly. Zeszon angrily growled at her. Ben also stared at her with anger. Gwen wondered what was going on. Later, Vilgax arrived again with the Bio-bots. Ben left Gwen in the HQ. Karat and Gwen met each other and asked what was the spell about. He didn't know. She opened the Archamada Book of Spells and found out that it was a spell of hatred. She used her magic to reverse the spell but it just gone the same. She was angry. She went into the fight and defeated the Bio-bots. Raphael arrived back from Pluto from a mission and found that there was a barrier out there. He crashed on Earth. He was uneffected by the spell. Gwen arrived at the spot. Gwen explained that Ka'rat had created a barrier to hatred. So Ben attacked Gwen. Ben took Karat's DNA. She forced him to turn into Karat's species. She hypnotized him and forced him to read out the spell. He read out and the barrier was gone, Vilgax dissolved into dust (which was part of the Spell's consequences). Gwen told the team the story, and laughed.
- Ben (fighting the Bio-bot 1): Duck!!!
- Tempeter (who saw a duck in the lake): Is the duck's life important than ours?
- Aguas (????):Uhh.....
- Ben: I said "DUCK" "Duck" not the Duck
- Tempeter: Could have fooled me!
- Raphael: Mission Accomplished
- Tempeter: Stop Accomplishing and come down here!
- Raphael: Oh, right
- Hammerhead: Hammerhead!!!!
- Karat: Karat!!!
- Gwen: Why do you have to shout out yourself? It's stupid
- Karat: To show my very heroic posture to everyone who is seeing this.
- Karat breaks the Fourth Wall
- When, Gwen asked Kevin about the transmitter, Kevin's eyes were purple and Gwen's sleeves were purple, they were same colour as the trasmitter's energy ray. In the next moment, her sleeves were in their original colour while Kevin's eye continued to be purple until the dinner.