Complex sentence: Bowser was the creation of Nintendo designer and producer Shigeru Miyamoto Miyamoto had first envisioned Bowser as an ox, basing him on the Ox King from the Toei Animation film "Alakazam the Great".
Split into simpler sentences: Bowser was the creation of Nintendo designer and producer Shigeru Miyamoto. He had first envisioned Bowser as an ox, basing him on the Ox King from the Toei Animation film "Alakazam the Great".