Final answer:
The "beastie" is a creature or supernatural being that elicits different reactions from the younger and older boys.
Step-by-step explanation:
The "beastie" in the context of your question refers to the presence of a creature or a supernatural being that is feared by the younger and older boys in different ways. In the first passage, the reaction of the boys is one of curiosity and disbelief, with the younger boys pressing their noses against the glass to get a closer look. In the second passage, the reaction is one of fear and repulsion, as the presence of the beastie is associated with wetness and streams running on their bodies. These reactions highlight the different perspectives and emotions that the boys have towards the presence of the beastie.