Another hard one. Always more difficult with things I've never heard of - 1D,20A,21D - so grateful for Quicksolve. I got 3D but spent an eternity trying to understand the clue.
Thanks Chrisg for info on RT34 thread.
AngelMCM - it's a huge hairy predecessor of the elephant. The first word describes what a jumper you wear is made of. Bon nuit.