A black and white picture of Mantra by Robb Phipps, casting a spell. (And probably feeling a bit of a draft, since she seems to have mislaid her armor again.)
Mantra Artwork
Adam Walters, 2001
A great color picture of Mantra looking beautiful when she's angry. 
Supermantra
Adam Walters, 2001
This is a fun little crossover piece that might have happened if DC bought out Malibu instead of Marvel...
Mantra and Green Lantern
Adam Walters, 2001
Another DC crossover piece by Adam Walters, this time with Green Lantern
looking to get on our heroine's good side. (Hey, GL...a little advice:
next time, spring for roses. The power ring trick is cute, but you aren't
going to win hearts with broccoli.)
Mantra Artwork
Daniel Veesenmeyer, 2001
A great color piece of Mantra, a little bit reminiscent of Patrick Nagel's style.
Mantra Artwork
Dave Hoover, 1994
A gorgeous ink drawing of Mantra, um, adjusting her armor. (Hey, I'll bet it chafes...)
Mantra Artwork
Pencils by Paul Ryan, Inks by Ande Parks, 1993
Mantra flying and wielding the Sword of Fangs.
Mantra Artwork
Adam Walters, 2001
Another great piece by the talented Adam Walters, with our heroine well
overdue for a hair styling. 
A proposed cover for the series, with Mantra and Boneyard having a little showdown.
A nice pen and ink of Mantra by Caesar (who did quite a bit of work on Vampirella).