Treecon

The Treecons are genetic experiments from the IDW portion of the Generation 1 continuity family.

Spawns of the Grand Architect's mysterious plans for the future of the Transformer race, the genetically-altered "Treecons" are a strange group of wooden Cybertronians who transform into trees. They're capable of using their unusual alternate modes to great effect in an ambush.

Fiction

IDW Generation 1 continuity

As the "Grand Architect," Scorponok had always been interested in advancing the evolution of his species. Centuries ago, during the final phase of the Great War, he began a series of wide-ranging experiments that involved the procurement of sentio metallico. An Axe to Break the Ice Chasing the Infinite

Following Scorponok's excape from Garrus-9, he and his cadre of scientists resumed his experiments, and one such development yielded what was evidently a prototype Treecon: a wooden robot who incorporated a mixture of soft circuitry and fibrous tissue. It died after the Worldsweeper it was "born" on crashed on the planet Clemency. Rules of Disengagement

Five years later, Nickel and the Scavengers encountered a horde of fully-formed Treecons on the planet Confluence, using their alternate modes to disguise themselves as a forest. When they revealed themselves, however, they were summarily torn to shreds by Grimlock. The Ties That Bind