There are many alternate endings of Ice Age 1 that never made it to theaters or DVD.
While fighting Soto and his pack of saber-toothed tigers, Soto is distracted by Sid, who is holding the baby, suddenly, Manny is about to knock Soto onto the wall, but he dodges Manny. Soto lures Manny to attack him, but Manny accidentally rams into the wall instead of Soto. Then, a bunch of icicles fall on Manny, slicing his head off and killing him. Soto and his pack of saber-toothed tigers eat Manny's dead body, then Soto banishes Sid and eats the baby. Sid was upset, but Soto sends some of his minions to pursue Sid. Sid runs from the tigers until they get tired. Poor Sid may never find friends with no one anymore. :(
Diego is trying to protect Manny from Soto, but then Soto bites Diego on his paw. Then, a TV officer teleports from the present-day using his futuristic watch and arrests Soto for biting Diego on the paw, and takes Soto to the present-day. At court, the judge finds Soto guilty and locks him up in TV Jail, a prison where characters from television go for doing bad things. In Soto's new jail cell, a security TV guard tells Soto that his "Punishment Day" is tomorrow. Soto is cries that he wants to go home, but then a security TV guard uses his taser to electrocute Soto. The guard also tells Soto that his cellmate is a Chain Chomp from Super Mario Bros.
While battling the saber-toothed tiger pack, Manny is about to knock Soto onto a wall, but then Soto surrenders and apologizes to Manny and Diego. They both appreciate it, and Soto joins the herd. The herd and the new members later return the baby to the humans and so the herd heads south and live happily every after.
While battling Soto, both Deigo and Soto hear a feminine voice and they looked and they saw Shira (from the 4th Ice Age film), they both got so attracted to her, but suddenly, Shira bites both Soto's and Diego's neck as she reveals her face, with a more vampiric appearance, Shira drinks the blood out of both male sabertooth tigers as she turns them into vampire sabertooth tigers. Then they attacked Sid and Manny, biting them and turning them into vampires too, with the baby Neanderthal running off until he finds his dad again by himself. But as for the animals, the vampire Apocalypse has begun.