Cybermat as seen in the four part Troughton episode 'The Tomb of the Cybermen' (1967)

Cybermat comprises part of the Character Options Cyber Controller Collect 'N' Build Wave

Two distinct versions of the Cybermat are included with Character's Tomb Cyberman

The Cybermat was first seen in the 1967 episode The Tomb of the Cybermen. Cybermats are deployed in the initial wave of stealth attacks using venom and electrocution. Homing in on the brain's electrical activity these palm-sized cybernetic organisms incorporate sophisticated anti-surveillance capabilities.

Thanks Hoosier Whovian

2011 Bump-N-Go Cybermat

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