Trantis the Third or Trantis III
Talk about it here.
Trantis III, the son of Trantis the Second and father of Trantis IV, and a member of the Syndicate who wanted revenge on the Doctor for his father's death on Kembel in 4000. Later in the 41st century, he headed the Syndicate's dream machine project when the Fourth Doctor and Ann Kelso arrived to stop him. When he used his species' defensive and poisonous facial tendrils to attack the Doctor after he was confronted, Kelso used a dream machine-controlled Sentreal to murder Trantis. (AUDIO: The Perfect Prisoners)