Tommy

Tommy – Be All My Sins Remember’d (4×11), Spoils Of War (4×12), Midway (4×17) –
Brendan Penny in Midway but conflicting information about who played him in Be All My Sins Remember’d and Spoils Of War.

WDC members decided that the Wraith in BAMSR and Spoils was the same one as in Midway because of the facial hair and distinctive chin tattoos. We have no idea how he managed to escape being blown up in Spoils, though.

He is also the Wraith known as Ember in the Stargate: Legacy book series, according to this blog by Melissa Scott.

Todd

Todd
Common Ground (3×07), The Seer (4×08), Miller’s Crossing (4×09),
Be All My Sins Remember’d (4×11), Spoils of War (4×12), The Kindred, part I (4×18),
The Last Man (4×20), The Queen (5×08), First Contact (5×10), The Lost Tribe (5×11),
Infection (5×17), Vegas (5×19), Enemy At The Gate (5×20) –
Christopher Heyerdahl

Except in Be All My Sins Remember’d – voiced by Heyerdahl but played by Brendan Penny and possibly Spoils Of War because there is conflicting information about who played him in this episode.

Appearance in SGA: Legacy as Guide

Michael

Michael (name given on the show)
Michael (2×18), Allies (2×20),
No Man’s Land (3×01), Misbegotten (3×02),
Vengeance (3×19), The Kindred, part I (4×18), The Kindred, part II (4×19), The Last Man (4×20) Search & Rescue (5×01), Prodigal (5×14) –
Connor Trinneer Except in Allies – voiced by Trinneer but played by Brent Stait and in his Wraith form played by James Lafazanos (not confirmed)

Mentioned in SGA:Legacy as Lastlight

Here are the human form and the Wraith form of Michael.