Tiberius, when first seen, is depicted as a hungry and vicious killer bird. He killed any animal who he caught and appeared to enjoy the killings. However, he is quite sensitive. He breaks down and cries when Gidget scolds him for attempting to murder and devour her. He then reveals he was born with "killer instincts" and he is very lonely and has no friends. He is then completely ecstatic and happy when Gidget propositioned being his best friend if he helped her find Max, her crush. His predatory instincts still pop up every now and then. He makes several attempts to eat Norman and tries to eat a bird, but Sweet Pea stops him.
The Secret Life of Pets
Tiberius is kept in a shed with a mask atop an apartment building. Gidget climbs up to the roof look for Max, Tiberius calls her tells her to come to the cage. He says he'll help her find Max if she lets him, so Gidget goes inside the shed and takes off his hood. Then Tiberus tries to eat her, chases her outside, but the chain on his leg stops him. Gidget gets mad, Tiberius apologizes says he's a predator with no friends. Though Gidget doesn't fully trust him, she understands so she tells Tiberius she'll be his best friend if he helps find Max. Tiberius agrees and Gidget takes off the chain, he then accompanies Gidget and her pet squad to find Max and Duke.
- He is going to be the secondary antagonist, one of the Flushed Pets, and Snowball's lieutenant. However when it is released, he becomes Gidget's best friend.