Satake

Foster is a character of the day who appeared in Fossil Fools (EP165). He is a Celadon University graduate who was taught by Professor Oak.

As a student, Foster had written a thesis that all life originated in the oceans, citing the fossil records as his main evidence. As an adult, Foster continued his studies and led a team of research Scientists to excavate the Ruins of Alph. Early on, it was discovered, among others, that the Spiral Pokémon Omanyte and Omastar were still living there. As a result, they made plans to open the Ancient Pokémon Study Park to showcase their findings to the public.

Foster invited Oak, who then invited Ash and his friends, to the Ruins of Alph so they could see the fossils. He initially lied to Oak and the others, saying the Fossil Pokémon he showed them were mechanical. However, Ash and his friends eventually saw through this after noticing that the Omanyte and Omastar were behaving in a way that looked too real for any of them to be robots. In fact, Foster tried to protect them because they were so rare.

After Team Rocket attacked the Ruins of Alph and tried to steal the Pokémon, both Foster and Oak thought it would be best to leave the Omanyte and Omastar alone, which Ash and his friends agreed to.

(Source: Bulbapedia)