Ubervamps were elderly undead creatures that are much different then a vampire. They don't drink animal blood or human blood at all, and they can survive without thirst.
Ubervamps are supernatural species in the Twilight universe. It is known that elderly humans can be turned into ubervamps. When an an old human is turned into an ubervamp, they don't consume any venom. If they ever bit someone, the person (he or she) will not turned into a vampire. Since Vampires were feral, predatory creatures, far more savage and beast-like than their human appearance suggests, Ubervamps are not like that at all. They are very peaceful, and they never take any grudge against vampires. Ubervamps are also capable of feelings, such as love, beauty, protection, compassion, care, respect, empathy and remorse.
Since a vampire's eye is either crimson red, gold, or burgundy, Ubervamps are much different. Their eye colors are sparkle with yellow colours, but they change their eye color to red with blue flames when they are in a state of fury.