Teucer was a character in Homer's The Iliad. He fought on the side of the Greeks, and his gift for archery provided an invaluable defense for the Greek camp. He was the illegitimate son of Telamon, and the half-brother of Ajax.
Teucer gained much fame during the Trojan War, and he returned home alive. However, his half-brother Ajax was not so lucky. Ajax quarreled with Odysseus over the possession of Achilles' armor. After the quarrel, he was put under a spell by a god, and he slaughtered a herd of sheep, thinking that they were Trojans. When regained his normal sense of perception, he killed himself rather than facing up to the ridicule of his comrades.
Telamon held Teucer personally responsable for the death of his half-brother Ajax, and Teucer was banished from his home.