Tubiel is named as the head of the sign of summer in the Heptameron.
The summer list
The English text places Tubiel under that heading. A separate heading lists Gargatel, Tariel and Gaviel as the angels of summer.
The name appears within the work’s sequence of seasonal names.
Source
Heptameron, or Magical Elements, seasonal list, Robert Turner’s English text in Joseph H. Peterson’s digital edition.