These Ultra Monster illustrations by Toshio Okazaki are from 'The Return of Ultraman' sonosheet book (Volume 1) published by Elm in 1971.
Gesura, MAT Sub [+]
Jirass, MAT Arrow 1, MAT Arrow 2 [+]
Gorbagos, Suflan, Kiyla [+]
Mognezun, Kemular [+]
Dorako, Ultraman, Gomora [+]
Alien Mephilas, Hydra, Jamila, Ultraman [+]
[More: Ultra Monster paintings by Toshio Okazaki]
(Via Pink Tentacle.)