Dragoncrest Cliffs All hail the poison berry!

prompt: Weather conditions are so favorable for fruit, that you character discovers delicious fermented fruit.

Summer was in full swing. The birds chirped, and fledglings tried out their wings. Dolphins splashed in the sea. Recently, colorful red berries popped up on bushes around the cliffs. Astera curiously observed the berries, knowing that the packs older members wouldn't approve of her eating foreign fruit. And yet the berries looked so juicy and Astera couldn't help wondering how they would taste. So when nobody was looking, she gingerly plucked a few berries off a bush and ate them. They tasted sweet and sour art the same time, and the overwhelming tase made Astera head spin. The world felt upside down and the cliffs started spinning. Astera staggered as she tried to walk and fell face flat on the ground. Her vision filled with colors that slowly faded back to normal. She looked in amazement at the berries and tried another one. This time there was no result. Hmmm... Astera wondered how many it would take to trigger the same reaction. Astera nibbled on the berries until her paws, mouth, and fur were stained with red and pink. Oh no! Would the stains come off? 

I thought this would be a fun prompt for @Miette, but AW, especially any pup.