I have a very limited understanding of the Monsters! Monsters! game. In essence, it is very similar to Tunnels & Trolls, using the the similar modifiers to the base rolled stats to create a character for the monster's view of the world - kidnapping and eating dirty human villagers, moving into a dungeon and setting up its defenses against those trespassing delvers, or just simply trying to amass a horde of like minded monsters to rampage and pillage.
Monster Menagerie does a wonderful job of presenting some new monster types for use with either game. My first opinion of the work is that I want more! There are some wonderful ideas for new monsters that the creative T&T GM can use and expand for his own use. Many special abilities are mentioned that could be expanded to be included as special attacks as a result of Spite rolls by the monsters to make them a bit more unique. The artwork is very distinct and nice touch to the overall look and feel for the tome.
There is a very expansive and creative list of spells for the mysterious 'Eeek' monster that sadly does not seem to have an illustration (either internally or in the cover image), unless the Eeeks are the glowing eyes in the background of the cover? I believe some of the spells could use a bit more information or examples regarding how they would work in a game, but just my own personal and selfish opinion.
More creative and inspired monster lists are something that I feel are definitely needed to support growth for the T&T game. For those that may be new to T&T, and with the upcoming release of Deluxe Tunnels & Trolls by Flying Buffalo, keep in mind that the basics of the game are quite consistent. This and many works by companies that support the game system are compatible across all rules editions.
This is a very good and promising start to what will hopefully be a series of supplements from this author. Who knows, maybe I need to give Monsters! Monsters! a chance at my table.