I have included my Call of Cthulhu to Alternity Conversion Notes, with examples, a method of applying the Call of Cthulhu skill advancement mechanic (Skill Ticks) in place of Achievement Points and levels, and conversions of the Insects from Shaggai (Shan), Servitors of the Outer Gods, great Cthulhu, Karotechia villain Reinhard Galt, Tcho-Tcho criminal mastermind Cho Chu-Tsao, and their Anthropomancy FX skills. Rules design by Jim Clunie, Word design and formatting by Charles Borges.

I've also posted some conversions by Charles Borges of the Deep Ones and Dimensional Shambler.

Or see the link to d20 Call of Cthulhu work.