Nemata

Nemata was one of the magnigoth lords from the forest of Yavimaya on Dominaria. He was over three thousand feet tall.

Storyline
Nemata was among the magnigoth treefolk who traveled from Yavimaya to Urborg to recapture the primeval dragon Rith, who originally had been trapped in a grove. Multani saw Nemata dwarfing the shagback hickories of Urborg, while the treefolk was swatting boughs through a swarm of dragon engines like a man struggles to drive off a swarm of bats.

His fate after the demise of Yawgmoth is unknown: only three treefolk are said to be present at the first anniversary of the end of the Phyrexian Invasion, but they aren't named.

Note
The magnigoth guardian in which Rith was imprisoned was never named, but it is heavily implied it was Nemata (however, its description in the books more closely resembles another magnigoth treefolk, Verdeloth the Ancient). Even the title of Nemata, "Grove Guardian", seems to confirm that he had the task to guard over Rith's Grove and the captive dragon.