I remeber a movie from probably late 80s/90s about a hobgoblin/dwarf/kobold who lived somewhere on/near a farm – in tunnels underground maybe – who always had to have gold/coins on him, in his pockets, otherwise he would blow up/get bigger ??? and disappear or something. I think he was ginger with a beard (kind of like a leprechaun).

He didn’t like children but he eventually befriended two siblings, boy and girl, and was helping them against probably an evil stepmother or something?

I remember it was happening on a farm and sometimes in a barn, I think at some point they were leaving coins under a metal milk can or something.

He also had like an  elaborate alarm clock or something?

It was a family movie, very likely that it was German or Dutch or something.

Please help!