Why do I am alook alike a poss of porter pease?

This is the first of the Prankquean's 3 riddles. Here are the riddles in order:

1. Mark the wans, why do I am alook alike a poss of porterpease? 2. Mark the Twy, why do I am alook alike two poss of porterpease? 3. Mark the Tris, why do I am alook alike three poss of porter pease?

The form of the riddles is based on the three times (wans, twy, tris) is a charm motif (used elsewhere in FW, for example in the tale of the Kerrse the Tailor and the Russian General). It is used in "the fairytale pattern of three tries and a magic opening" (Margeret C. Solomon, Eternal Geomater).

Porter = a door keeper and ale.

The riddle sounds like: why do i and a poss of porter look as alike as two peas in a pod?