>>95860281That's a fairly standard example of 3.5/PF statblock skill bloat, where the writers for some reason feel the need to list every skill a creature could theoretically have, and then those skills get massive bonuses due to high CR monsters having extremely high stats.
The Illithid Elder Brain, a literal giant brain floating in a pool of liquid, somehow having +20 on disguise self is probably the funniest example.