Second Doctor

Though outwardly warm, bumbling and clownish, the Second Doctor also had a darker, more cunning aspect to his personality — one which he usually kept hidden in order to carry out his plans. Regenerating when his first incarnation gave in to old age and fatigue following his fight with the Cybermen, this new incarnation was the product of the Doctor's first regeneration.

He travelled with a number of companions, starting with his previous incarnation's last companions, Ben Jackson and Polly Wright, before adding Highland Scot Jamie McCrimmon to the TARDIS. After a while, Ben and Polly left, to be replaced by Victoria Waterfield, a woman orphaned by the Daleks. In time, she too left, and the Doctor made a new friend in the mentally gifted Zoe Heriot. When This doctor was exiled to earth, he was scientific advisor of UNIT with Rebecca Shaw.

Season 4 (1966-1967)
The Tenth planet

Power of the daleks

The Highlanders

The Underwater Menace

The Moonbase

The Macra Terror

The Faceless Ones

The Evil of the Daleks

Season 5 (1967-1968)
The Tomb of the cybermen

The abominable snowmen

The Ice warriors

The Enemy of the world

The Web of fear

Fury from the Deep

The Wheel in space

Season 6 (1968-1969)
The Dominators

The Mind Robber

The Invasion

The Impersonators

The Krotons

The Aliens in the Blood

The Laird of the McCrimmon

The Correctors

Season 7 (1970)
Spearhead from Space

The Mind of Maringus

Invaders from Mars

The Mists of Madness

Season 10 (1972-1973)
The Three doctors

20th anniversary special (1983)
The four doctors

30th anniversary special (1993)
The Invasion of Tempus