The Turtle is one of the guardians of the Beams that support the Tower at the center. His physical form in Jovoy is presumably a cyborg like Shadik. It is hinted that this Beam is personified in the character of Michael “Crow”. In actuality the turtle's true form is much more grand and powerful. There is evidence of this in several occasions when it has come to aid Michael and others. It also bears resemblance to the Word turtle found in Hindu myth.
The poem written about Maturin is featured prominently within the series. Only the first two lines are mentioned frequently.
"See the Turtle of Enormous Girth"
"On his shell he holds the Earth."
"His thought is slow, but always kind."
"He holds us all within his mind."
"On his back all vows are made;"
"He sees the truth but mayn't aid."
"He loves the land and loves the sea,"
"And even loves a child like me."