The Sphinx was the gaurdian of Thebes in Greek mythology. In answer to your question, no one really 'killed' her, except indirectly. She basically comitted suicide because Oedipus solved her ridlle.
"Which creature in the morning goes on four legs, at mid-day on two, and in the evening upon three, and the more legs it has, the weaker it be?" She strangled and devoured anyone unable to answer. Oedipus solved the riddle by answering: Man-who crawls on all fours as a baby, then walks on two feet as an adult, and then walks with a cane in old age. By some accounts[5] (but much more rarely), there was a second riddle: "There are two sisters: one gives birth to the other and she, in turn, gives birth to the first." The answer is "day and night" (both words are feminine in Greek).
Python was the name of a monster killed by Apollo. Other monsters were killed by Zeus and Hercules.
In Greek mythology, Python was a giant serpent or dragon that lived at Delphi and guarded the Oracle of Gaia. According to myth, Apollo slew Python to claim the sacred site and establish his own oracle there. This victory symbolized the triumph of order over chaos and marked Delphi as a major religious center in ancient Greece.
Apollo shot Python with his golden bow.
In Greek mythology, the dragon Python was killed by the god Apollo. According to the myth, Python guarded the oracle at Delphi and was eventually defeated by Apollo during a fierce battle. After slaying the dragon, Apollo established the Pythian Games in honor of his victory and took over the oracle, which became one of the most important oracles in ancient Greece.
Bellaphron killed the chimera
Theusus
Delphi is a Greek city where Gaia sent Python (a huge serpent) to guard the oracle. Apollo laid claim to the shrine and killed Python, apparently to avenge his mother Leto who had been pursued by Python during her pregnancy.
Greek gods are considered immortal beings in Greek mythology and cannot be killed in the traditional sense.
In Greek mythology Erebus is not said to have killed anyone.
Theseus did.
Theseus killed the minotaur
Theseus in Greek mythology was the hero who killed the Minotaur. He was journeying around Greece and arrived at Crete. There he killed the Minotaur. He is supposed to have been the founder and first king of Athens.