The gibberling is a monster added in SLASH'EM. They are remarkable for appearing in very large groups, but are otherwise weak and likely will not be a large threat as they can only be generated in Gehennom.
Take note however, that eating a gibberling as a human, is considered cannibalism.
Yet an other monster that was borrowed from Dungeons and Dragons.
They look simian with pointed ears. They are primitive and have no language.