The Thir Bush is a COB by Markham Carroll for Creatures 2 (the C1 original was known as the Training Plant). It is intended to teach Norns that eating plants is a good idea.
Fruit from the Thir Bush may have the following effects (assuming it's the same as the C1 version):
The Thir Bush can be downloaded from Markham's Norn Land. It includes its own seed launcher.