My favorite character of mine was Wilhelmina Brochenbach from
Assigned to Mordor... my favorite character someone else wrote is
Primrose Bolger's Sassy Brandybuck from
Sailing Away. I remember Prim wanted us to leave her character alone so she could work on her own storyline for Sassy, and it turned out very well (if sad). Oh! And
Firefoot's Grimkul and Ulwakh in
Red Flows the Sirannon were two really nifty characters as well.
