Sorry, but the sheer implausibility of this episode makes it one of the series' weakest offerings. If the normally reserved Ross were really interested in teaching Ben about Judaism, would dressing as an ARMADILLO be the most likely way for him to go about it? (Rachel's line about the Easter Bunny's funeral was good, though.) And if Phoebe were really close friends with Rachel, wouldn't she already know how she would react to drums and tarantulas? (We won't even go into Phoebe's ability to buy expensive gifts.)
Whenever the writers feel the need to ransack the wardrobe and prop departments to generate laughs, that's a danger sign.