What literary feature is in Lucille Clifton's "Moonchild"?

Lucille Clifton's "Moonchild" is a short poem, only four stanzas, but there is a great deal going on. I'll help you examine literary features in each stanza.

Let's start with the first three lines:

"whatever slid into my mother's room that/late june night, tapping her great belly/summoned me out roundheaded and unsmiling."

The use of the indefinite pronoun "whatever," which begins the poem, suggests ambiguity and the unknown. "My mother's room" has double-meaning: it could be a literal room, or the womb. Here, then, we have the possible use of metaphor. Entry into either room -- or both -- results in the birth of the narrator.

The next three lines:

"is this the moon, my father used to grin/cradling me? it was the moon/but nobody knew it then."

In this poem, the moon is linked to womanhood, which becomes clearer in the next stanzas. Culturally, the cycles of the moon are linked to menstrual cycles, which is later suggested. The narrator's father [cradles] her, much as the sky cradles the moon. Thus, an analogy is made here: father is to daughter as sky is to moon. 

In the second stanza, Clifton employs anaphora, which is the repetition of particular words or phrases at the beginning of each line. The purpose is to create a particular effect on the reader through the emphasis of these words or phrases. The narrator repeats "the moon." Then, in the third line, the moon becomes "she." The moon is feminized. Here, one could argue that the moon is personified, or anthropomorphized, as female.

In the third stanza, there is a jump in time to early girlhood and pubescence. There is the narrator's recollection of a dialogue between her and another little girl:

"jay johnson is teaching me to french kiss, ella bragged, who/is teaching you? how do you say; my father?" 

There is an interesting use of voice in these lines. It is a recollection in which her friend Ella speaks -- brags -- and the narrator, in the moment, says nothing. Now, in her recollection, she ponders how she could have spoken the truth of her experience, which was sexual abuse. There is a contrast, too, between Ella's bragging -- her fluency in describing her sexual exploration -- and the narrator's inability to find the right words.

In the last stanza, there is the use of hyperbole:

"the moon is the queen of everything/she rules the oceans, rivers, rain."

The moon, because it determines the ebbs and flows of oceans, and thus, rivers and rain, becomes "the queen of everything." Finally: "when I am asked whose tears these are/I always blame the moon." It is only in these last two lines that the narrator asserts her voice and becomes "I." Notice, too, that "I" is the only word that is capitalized in the entire poem.

The last lines allude to menstruation: the narrator is crying and blames "nature," or "the moon," for her tears, her moodiness. This reflects the cultural tendency to point out women's unpredictability due to the fluctuations of the womb. She is asked (notice the use of the passive voice) "whose tears these are," which is a denial of her identity and agency. So, she blames the moon. The narrator is being cheeky. She is also asserting her identity ("I"), her voice (active tense is employed for the first time with the phrase "I always blame"), and her steadfastness with the use of the adverb "always."