Basically it is scarecrow tig.
Select a Beaver to be Dr Who. and two others to be Daleks. They can be identified by turning their scarves round. The remainder of the Beavers are Heroes. On the word 'Go" the Daleks chase and touch the heroes saying 'exterminate'/ The exterminated heroes then freeze until they are set free by Dr Who crawling through their legs. Change the leading characters frequently.