Lycanthropes in Holmes follow the general outline established in the LBBs and Supplement I. Again, as with dragons and giants, all can be of Neutral alignment, as well as some other alignment. There's no discussion of the social structure of these creatures, as there is in OD&D. Manticores get a name change from manticoras. Medusas are as in OD&D, but it's noted in Holmes that "This monster is usually female," implying that there are male medusas. Minotaurs are identical to the LBBs, right down to the joke about rules lawyers being bull-headed. Mummies acquire their ability to frighten those who see them in Holmes (or, rather, in the Monster Manual, but Holmes follows suit). Ochre jellies and ogres are as in OD&D. Orcs are very similarly presented, but there's much less detail on the contents of an orc lair in Holmes than there is in the LBBs.
Owl bears and pegasi are mostly unchanged. Pixies drop any reference to Chainmail and are noted as being "friendly with elves and fairies," the latter of which corresponds to no creature in Holmes or OD&D. Purple worms aren't much changed, but they swallow opponents more easily than in OD&D, requiring only 2 more than the needed number of 1D20, whereas in OD&D they need 4 more to do so. Rust monsters follow Greyhawk. Shadows remain incorporeal creatures that are not counted among the undead. Shriekers appear here, an import from the Monster Manual. Skeletons and spectres are unchanged and Holmes explicitly connects spectres to the Nazgûl of Tolkien. Spiders get a full write-up, as in AD&D and notes that giant spiders are both intelligent and chaotic evil in alignment.
Stirges from Supplement I appear and troglodytes from the Monster Manual appear (though the latter first appeared, I believe, in The Lost Caverns of Tsojconth tournament module). The troll entry is nearly identical to that in OD&D, including the description of them as "thin and rubbery." The unicorn entry is interesting for a couple of reasons. First, it makes reference to the dimension door spell, which is nowhere described in Holmes. Second, the OD&D entry specifies that "they resist magic as if they were an 11th level Magic-User," while Holmes states taht "they resist all magic on a roll of 8 or better on a 20-sided die." Now, it's true that an 11th level MU has a save of 8 against spells in OD&D, so it's almost certainly the case that Holmes meant the two rules to be identical. However, as a young man, I took this to mean something above and beyond a saving throw.
Vampires follow OD&D, with the additional clarifications presented in Supplement I. However, Holmes is stronger in noting that holy symbols other than a cross are effective against vampires, an option which Greyhawk leaves to the referee's discretion. Wights and wraiths are as per OD&D, though Holmes (again) makes a connection to Tolkien, this time in reference to wights. Yellow mold and zombies follow OD&D. Interestingly, the zombie entry notes that, in addition to sleep and charm spells like all other undead, zombies are also immune to ESP, which is peculiar.
And that wraps up the monsters of the Blue Book. I'll reiterate that I found it interesting how much Holmes lifts straight from the LBBs, right down to whole blocks of text. The stats are similarly nearly identical to those in OD&D, with only a few small changes here and there, many of which, I suspect, are reflective of changes in the Monster Manual, the only AD&D book released at the time of the Basic Set's completion and one that, as others have repeatedly shown, is itself a lot more reflective of OD&D than is commonly supposed.