Small creatures for polymorph

[Melnir]

My PC is a grey elf wizard 9/IotSV 3. Since I use lot of ray spells, I'm looking for a small form, better with good dex score (14 or higher), that can cast spells. I can use only creatures from MM 1-2-3, FF and BoED. Thank you!!

[Evolved Shrimp]

Any of the sprites (MM p235/236) should do nicely.

[Vaz]

Spriggan from the fiend folio. 20 Dex and small sized.