When I ran Goodman's "Into the borderlands" I used the AD&D 2e monstrous manual to fill in the gaps for monsters I did not choose to replace.
"We alone of all mankind, who are sorcerers of high attainment and mastery, may endure the lethal ice-change and become breathers of the airless void, and thus, in the end, be made suitable for the provender of such as Rlim Shaikorth." sounds great unless you know what Provender means.