A useless creature that is formed when a balrog mates with a lobster, resulting in a lobster beast with flaming feeler (palp) which effectively cooks their own body. This is ironic because they can only utilize these flaming feelers when out of the water (their natural habitat) at risk of cooking themselves, additionally that means they are not effective in battle in their natural habitat as they cannot utilize their flaming feelers. Thus a lobrog can be defined as someone who is very useless.
When a reviewer or critic who gets into a tradeoff of critical praise or "You scratch my back, I'll scratch yours" situation. Implicitly or by agreement, one reviewer exchanges praise (often fatuous) with another in the hopes his inflated regard will find its way into publicity, advertising copy, book-jacket blurbs and the like and increase the other's visibility (and sell more books). The favor is expected to be returned, and at some point is. Probably descended from the literal use of logrolling as a pioneer sport, in which neither participant can stay on the round, floating timber unless one is pedaling frantically one way, one the other, although the symbolism invoking a mutual-gratification pact analogous to masturbation cannot be denied.
In the 1980s, SPY magazine ran a regular column called "Logrolling In Our Time" giving exact instances of such tit for tat.
-- "Oh, God. This is logrolling at its worst. A___ says on the dust jacket of B____'s new novel that 'a new American voice is born.' Three months later B____, now bestselling author, says that A____'s latest textbook is 'unchallengeable in its supremacy in this field.'"
-- "They belong to a mutual admiration society, intellectually speaking."
-- "I'm sorry; did you say "intellectual mastur---"