Gororo

Gororo (ゴロロ) is the guardian ghost of Usui Oyaji. He is a Koropokkoru(known as Minutians in the English anime). Because of his unnatural size he has been shunned by the other Koropokkorus

Past
Gororo apeared in front of Korobe Tamiko(Nicknamed Damuko) when she died. When Damuko refused to leave this world he gave her the choice to stay and become a nature spirit.

Anime/Manga Difference
Because Oyaji never appeared in the anime, Gororo didn't either.