The Announcer has never had a psychical form. While this character is not seen, he shares a similar voice to Archibald and Scallion 1. Larry even mentioned to Archie that he always thought he was the announcer.
His voice was distantly different in his first appearance, then a bit higher in his later appearances. As the series progressed, he switched voices with Scallion 1.
Since Phil Vischer voiced him, some fans speculate that he may have been Archibald as the voice is similar to his, only more softly (also because his robot counterpart, from the Veggie Carnival computer game, played the part for The Hairbrush Song). However, this was debunked in The Biscuit of Zazzamarandabo as Archibald confesses to Larry that he thought he was the announcer.
Some would even say Scallion 1 may be the voice, as the Announcer in the later songs sounded more close to the former. This, too, was also debunked as Phil had confirmed on Twitter that the Announcer is just the announcer, not a vegetable.
However, in the credits of most episodes, the Announcer is being treated as a separate character. He had never psychically appeared in-person.
The Announcer appeared in nearly every Silly Song.