Wendy is a cow - but not just any cow. She's had quite a bit of excitement out in the dry plains lately, getting lost and having an... interesting time with a large feral gryphon. As you walk up to her stall, she gives a greeting 'Mooh', seemingly recognizing you. Then she turns, moving her hindquarters in your direction and looking back at you. Might just be your imagination, but it's a bit as if she was presenting herself to you, wanting a little more interspecies attention.
In the Dry Plains, the player may run in to one of two events. The first is Cow Hunting, where Corbin asks if you've seen his missing cow, Wendy. This allows the player to travel to the McDermott Farm where Anthony will ask the same of the player. Wendy can be found in the Dry Plains through the Missing Cow event, but it isn't necessary to speak with either Corbin or Anthony for this; the McDermott farm will be revealed automatically as the player leads Wendy back there. Speaking with Anthony afterward, the player receives four food as a reward.
If the player is so inclined, they may have sex with Wendy before returning her. She is also available for sex once she has been returned to the farm.