It's probably supposed to be Small Clanger.
Looking at
http://www.clangers.co.uk/ gives a wealth of information. Did you know that part of an episode of the Clangers was shown in an episode of Dr WHo? No, neither did I.
I liked the story told by Oliver Postgate about the the time he took an episode to show at an international show without the customary English commentary:-
'I took an episode of The Clangers to the 1984 E.B.U. conference in Germany and showed it to the participants without my voice-over. Afterwards I asked them whether they had been able to understand what the Clangers were saying.
"But of course." they replied. "They are speaking perfect German."
"But no." said Gerd, "That is not so. They spoke only Swedish," '
Wonderful!
PaulR
Also, try reading up about the swearing on the Clangers - apparently it was true.