NOTE: There is an error in the article. Beasts only get 10-15 total skill points (regardless of Hit Dice and/or Intelligence). They do not get the advancement range listed in this article. This is contained in the errata for the Monster Manual and is official.

Another error: In the "Calculating Save DCs" section it says to use "1/2 the monster's EXTRA hit dice." This is an error. Save DCs for a monster's special attacks are "10 + 1/2 HD + relevant ability modifer" (as stated in the DMG, MM, and elsewhere in this article). The Sage has confirmed this and it is official.