A. Ligator is the staff announcer on Muppets Tonight.
Despite what his name might imply, he's a vulture described by the Muppets Tonight style guide as Don Pardo-like. His voice and function are identical to the Announcer from The Muppet Show, even going so far as to shout "Pigs in spaaaace!" when introducing "Pigs in Space: Deep Dish Nine."
Unlike the Muppet Show announcer, who remained unseen until the final episode, the Muppets Tonight announcer was fairly visible as well as vocal, seen in the announcer's booth in the premiere and in several subsequent episodes.