"Drive Thru Worker" is not an official name. It may have been referenced by ids5621 as such, but has not been officially named. Alternatively, it may be a name popular among fans, but has no official basis.
The Drive Thru Worker is an unnamed Matoran who works at Tohunga Burger that made fun of Imutii through the drive thru speaker.
In the episode "Drive Thru", he takes Imutii's order, whilst mocking his decision. After Imutii is consumed by The Mysterious Hand, he laughs wickedly through the drive thru speaker, though immediately after it's shown that he wasn't paying attention and was just reading a newspaper comic he found humorous.