I assume then that the pollywog is now out of the door?
The termination here means nothing offensive - it's a derivation from middle English, for "wiggle". The noun is entirely descriptive - a head with a wiggle. Indeed, in the potential speciesism, I would defend to the utmost its use. It's alternative, tadpole, is not synonymous but refers merely to one creature - the middle English version of a toad-head.
What then of all the other larval forms, such as our humble frog? Must she/he/it/they/e/ey suffer linguistic discrimination and potential exclusion?