In my opinion, the producers of Space: 1999 were pretty gutsy in creating a fully metamorphic character -- Maya -- with mid-1970's technology.

They did it in several different ways. I do not really know enough details of camera, editing, and special effects terminology to know the correct names for these techniques, so I'll just describe them in whatever terms I can think up, and present specific examples where I can remember them.

• Fade-together: fading out humanoid Maya as another form fades in (or vice versa).
  • "The Metamorph": reverting from ape to a crying Maya as she stared at everything she had known going up in flames, her father already dead.
  • "The Exiles": to and from an ape-like (but alien-looking) creature.
  • "A Matter of Balance": very nice fade as Maya reverts from Shermeen's form. Their expressions and angles towards the camera are nearly identical too.
• Jump-away: shot of Maya about to transform or revert, then jump to shot of another character, then back to a transformed/reverted Maya. Sometimes this was done in a simple way; but sometimes, Catherine Schell provided an extra, like taking facial expressions or bodily movements reminiscent of the creature she was about to become.
  • "The Metamorph": Maya (as herself) snarls at Commander Koenig as he tries to block her from rushing into the fire to save her father, Mentor. Jump to Koenig looking a little shocked at her expression (and after having just fought her in bird-of-prey form). Jump back to Maya, and she is now a snarling canine. One of the morphs on this webpage is of exactly this transform, done as a morph rather than a jump-away.
  • "The Exiles": Reverting from Helena to herself off-camera, while John provides a reaction shot in between.
• Instant: Maya in one frame, transformed in the next, though again, sometimes Catherine Schell provides some extra "framing" via her acting.
  • "The Exiles": Maya has intense expression, extends arms into air, starts jumping, and the next frame, she is a puma in mid-jump! Very startling. Slow motion reveals the camera angle is somewhat different, but seen at regular speed, and with the others' reactions too, it was still nicely done.
• Eye-closeup: Focus on Maya's eye with image of target form within, then show that form, full-sized. Started right away with "The Metamorph" -- and was reasonably effective at conveying the point, if not in any special way. It was the most common means of conveying her metamorphoses.
• Blocking: One of the characters walks in front of Maya, blocking the view of her, and after the person has walked by and we see her again, she is transformed or reverted.
  • "New Adam New Eve"
• Swipe:
  • "The Dorcons": Maya to bipedal lizard-like creature and back, with what (in my extremely minimal knowledge of film-making) appears to be a camera or editing "swipe" effect. Okay and quick, but rather abrupt.

Though effective (to varying degrees) at conveying the point and sometimes in a visually-startling way, the ability to "morph" someone's image has come a long way.