Animo used to be a promising scientist until it was found he was performing twisted experiments on a animals. He was driven mad when he didn't get an award called the Verties Award. He uses a device called the Transmodulator to mutate animal DNA. He first met Ben when he attempted to get revenge on Dr. Kelly the man who got the Verties Award and looking for parts to complete his Transmodulator. He was able to finish the Transmodulator and went into the second phase of his work, reanimating dead cells. He attacked Kelly with a resurrected T-Rex, but was defeated by Ben.

Dr Animo's return

Dr Animo returns and takes over an abandoned observatory and constructs his Transmodular. He then uses his intelligence and equipment to track down Ben and his friends and sought revnge with them. Ben and his friends were celebrating a happy festival and Max notices something wrong with the animals. Suddenly, a large mutated frog leaps out of nowhere and begins to attack the Ben and the rest of the audience there. Ben immediately recognizes the frog as one of Dr Animo's pets and then decides to use the omnitrix. However, Ben messed up with the omnitrix before the attack came which caused the front cover of the omnitrix to fall off. Without the cover, Ben was unable to transform into one whole being as the front cover shows the alien image. The omnitrix creates Stinkarms, an alien which has the wings and the head of Stinkfly and the body of Fourarms. Ben reckons he hed unlocked a new alien and uses his new form to defeat the mutated frog. The frog jumps on top of Ben as the frog wanted to squash Ben. Ben lifts the frog up but realizes that he was no longer as strong as before which caused the large frog to squash Ben. Ben then tries to fly but his weight was too heavy. Ben eventually punches the mutated frog which caused the frog to hit Dr Animo. Dr Animo then discovers a piece of the omnitrix and orders his pet to take him back to the observatory. Bne then reveals to Gwen and Max that he had brok the omnitrix by accident.

Dr Animo then decides to use the front cover of the omnitrix as his source of power. He then powers up his Transmodular and sees a bat nearby and uses the Transmodualr on the bat which mutates the bat and turns the bat into a Heatblast bat. He then commands the bat to ambush Ben and his friends but Ben transforms into a wierd alien combination called Diamond Matter. Ben, with the help of his close friends, defeats the Heatblast bat and follows the Heatblast bat to the observatory. Ben demands back the fragments of the omnitrix but Dr Animo refuses. Dr Animo claims that the fragment of the omnitrix is a piece of valuable technology and the potential power of it is vitually unlimited. He then empowers the Transmodular and fires it at Ben but Maxwell Tennyson takes the blast instead and mutates Max. Dr Animo fires another blast at Ben's altered state and was proven immune to Dr Animo's Transmodular.

Ben then transforms into a Ripjaw-Heatblast being. He struggled to defeat Dr Animo's pets at first but gets used to it when he is in water. Ben wounds the Heatblast bat and the mutated frog and challenges Dr Animo. Gwen secretly sneaks into the Transmodular cannon and steals the fragment of the omnitrix which depowered the Transmodular. Dr Animo then tries to get back the fragment but was knocked out by Ben. Gwen then returns Max back to noramal by turning the fragment upside down which negates the Transmodular's previous effect on Max. Ben then sticks the cover of the omnitrix back on before he turns back human again and the fragment sticks on.

He later appears having escaped from Alcatraz Island. He kidnaped Ben when he discovered a new self-replicating alien named Ditto. Animo combined Ditto's DNA with Stinkfly's to create an army of self-replicating giant insects. However Ben was able to destroy them when he relised that like Ditto they would feel each others pain and if he destroyed one they would all die. Ben defeated Animo's army and sent him back to prison.

Dr Animo built a machine which allowd him to travel to the future and Dr Animo built himslf an ape suit. He was increasing his power until Gwenalin, Gwen's future form, brings Ben and Gwen to the future and wants them to defeat the all-powered Dr Animo. Dr Animo then attacks Future Ben and claims that he would use the DNA structures in the alien room and create an army of powerful aliens. He easily defeats Future Ben and Ben himself and breaks the containner which holds Vilgax. Dr Animo then uses his advanced technology and brings Vilgax back to full form again. Dr Animo then tries to open the Null Void but was stopped by Future Gwen and Gwen. Dr Animo tried to escape, but failed as Gwen stepped onto one of his connectors.